Номер 775, страница 190 - гдз по геометрии 10-11 класс учебник Атанасян, Бутузов

Геометрия, 10-11 класс Учебник, авторы: Атанасян Левон Сергеевич, Бутузов Валентин Фёдорович, Кадомцев Сергей Борисович, Позняк Эдуард Генрихович, Киселёва Людмила Сергеевна, издательство Просвещение, Москва, 2019, коричневого цвета

Авторы: Атанасян Л. С., Бутузов В. Ф., Кадомцев С. Б., Позняк Э. Г., Киселёва Л. С.

Тип: Учебник

Издательство: Просвещение

Год издания: 2019 - 2026

Уровень обучения: базовый и углублённый

Цвет обложки: коричневый с ромбами

ISBN: 978-5-09-103606-0 (2023)

Допущено Министерством просвещения Российской Федерации

Математика: алгебра и начала математического анализа, геометрия

Глава 7. Метод координат в пространстве. Движения. Параграф 3. Движения, дополнительные задачи - номер 775, страница 190.

App\Models\Task {#1030 // resources/views/models/task/default.blade.php
  #connection: "mysql"
  #table: "tasks"
  #primaryKey: "id"
  #keyType: "int"
  +incrementing: true
  #with: []
  #withCount: []
  +preventsLazyLoading: false
  #perPage: 15
  +exists: true
  +wasRecentlyCreated: false
  #escapeWhenCastingToString: false
  #attributes: array:24 [
    "id" => 745190
    "created_at" => "2026-04-10 13:58:26"
    "updated_at" => null
    "field_page_start" => "190"
    "field_page_end" => null
    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik/00-775"
    "field_display_title" => "775"
    "field_outside_task" => null
    "field_task_type" => Illuminate\Database\Eloquent\Collection {#1037
      #items: array:1 [
        0 => App\Models\Term {#1036
          #connection: "mysql"
          #table: "terms"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: false
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:6 [
            "id" => 26
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "name" => "номер"
            "field_cases" => array:6 [
              "field_accusative_case" => "номер"
              "field_creative_case" => "номером"
              "field_dative_case" => "номеру"
              "field_genitive_case" => "номера"
              "field_nominative_case" => "номер"
              "field_prepositional_case" => "номере"
            ]
            "field_short_name" => ""
          ]
          #original: array:6 [
            "id" => 26
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "name" => "номер"
            "field_cases" => array:6 [
              "field_accusative_case" => "номер"
              "field_creative_case" => "номером"
              "field_dative_case" => "номеру"
              "field_genitive_case" => "номера"
              "field_nominative_case" => "номер"
              "field_prepositional_case" => "номере"
            ]
            "field_short_name" => ""
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "field_metatags_title" => null
    "field_metatags_description" => null
    "field_h1" => null
    "field_description_top" => null
    "field_description_bottom" => null
    "field_match" => null
    "breadcrumbs" => []
    "edition_groups" => Illuminate\Database\Eloquent\Collection {#1035
      #items: []
      #escapeWhenCastingToString: false
    }
    "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1079
      #items: array:1 [
        0 => App\Models\Branch {#1034
          #connection: "mysql"
          #table: "branches"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:24 [
            "id" => 744405
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Метод координат в пространстве. Движения"
            "field_branch_order" => "7"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1039
              #items: array:1 [
                0 => App\Models\Term {#1038
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:7 [
                    "id" => 29
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Глава"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => null
                  ]
                  #original: array:7 [
                    "id" => 29
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Глава"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => null
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "160"
            "field_branch_display" => "0"
            "field_branch_expanded" => "0"
            "field_display_branch_in_title" => "1"
            "field_display_task_interval" => "0"
            "field_display_branch_page" => "1"
            "field_branch_title_in_content" => "0"
            "field_navigation_title" => null
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1040
              #items: array:1 [
                0 => App\Models\Book {#1041
                  #connection: "mysql"
                  #table: "books"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:50 [
                    "id" => 36
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_tree_default_status" => "tasks"
                    "field_pages_status" => null
                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1042 …2}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1044 …2}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1047 …2}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1049 …2}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1055 …2}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1056 …2}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1058 …2}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1060 …2}
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1062 …2}
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1063 …2}
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1064 …2}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1066 …2}
                    "field_publication_number" => "11"
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1068 …2}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1070 …2}
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => "с ромбами"
                    "field_publication_year" => "2019"
                    "field_publication_year_until" => null
                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебник для общеобразовательных организаций"
                    "field_allowed" => "Допущено Министерством просвещения Российской Федерации"
                    "field_reserve_field" => "Математика: алгебра и начала математического анализа, геометрия"
                    "field_link_to_source" => null
                    "field_tasks_count" => "1147"
                    "field_priority" => "12"
                    "field_default_folder" => "/geometrija_10/atanasjan-u23/"
                    "field_isbn" => "978-5-09-103606-0 (2023)"
                    "field_cover" => array:1 [ …1]
                    "field_cover_alts" => array:1 [ …1]
                    "field_covers" => array:1 [ …1]
                    "field_popular_book" => null
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1071 …2}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1072 …2}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1073 …2}
                    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1074 …2}
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [ …3]
                  ]
                  #original: array:50 [
                    "id" => 36
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_tree_default_status" => "tasks"
                    "field_pages_status" => null
                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1042 …2}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1044 …2}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1047 …2}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1049 …2}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1055 …2}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1056 …2}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1058 …2}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1060 …2}
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1062 …2}
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1063 …2}
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1064 …2}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1066 …2}
                    "field_publication_number" => "11"
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1068 …2}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1070 …2}
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => "с ромбами"
                    "field_publication_year" => "2019"
                    "field_publication_year_until" => null
                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебник для общеобразовательных организаций"
                    "field_allowed" => "Допущено Министерством просвещения Российской Федерации"
                    "field_reserve_field" => "Математика: алгебра и начала математического анализа, геометрия"
                    "field_link_to_source" => null
                    "field_tasks_count" => "1147"
                    "field_priority" => "12"
                    "field_default_folder" => "/geometrija_10/atanasjan-u23/"
                    "field_isbn" => "978-5-09-103606-0 (2023)"
                    "field_cover" => array:1 [ …1]
                    "field_cover_alts" => array:1 [ …1]
                    "field_covers" => array:1 [ …1]
                    "field_popular_book" => null
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1071 …2}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1072 …2}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1073 …2}
                    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1074 …2}
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [ …3]
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1076
              #items: []
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 744405
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Метод координат в пространстве. Движения"
            "field_branch_order" => "7"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1039}
            "field_page_start" => "160"
            "field_branch_display" => "0"
            "field_branch_expanded" => "0"
            "field_display_branch_in_title" => "1"
            "field_display_task_interval" => "0"
            "field_display_branch_page" => "1"
            "field_branch_title_in_content" => "0"
            "field_navigation_title" => null
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1040}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1076}
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1120
      #items: array:2 [
        0 => App\Models\Branch {#1128
          #connection: "mysql"
          #table: "branches"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:24 [
            "id" => 744405
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Метод координат в пространстве. Движения"
            "field_branch_order" => "7"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1132
              #items: array:1 [
                0 => App\Models\Term {#1129
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:7 [
                    "id" => 29
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Глава"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => null
                  ]
                  #original: array:7 [
                    "id" => 29
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Глава"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => null
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "160"
            "field_branch_display" => "0"
            "field_branch_expanded" => "0"
            "field_display_branch_in_title" => "1"
            "field_display_task_interval" => "0"
            "field_display_branch_page" => "1"
            "field_branch_title_in_content" => "0"
            "field_navigation_title" => null
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1168
              #items: array:1 [
                0 => App\Models\Book {#1131
                  #connection: "mysql"
                  #table: "books"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:50 [
                    "id" => 36
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_tree_default_status" => "tasks"
                    "field_pages_status" => null
                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1133
                      #items: array:1 [
                        0 => App\Models\Term {#1130
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:10 [
                            "id" => 6477
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Геометрия"
                            "field_abbreviated_name" => null
                            "field_cases" => array:6 [ …6]
                            "field_foreign_lang_name" => null
                            "field_short_name" => null
                            "field_subject_type" => "technical_subject"
                            "field_translit" => "geometrija"
                          ]
                          #original: array:10 [
                            "id" => 6477
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Геометрия"
                            "field_abbreviated_name" => null
                            "field_cases" => array:6 [ …6]
                            "field_foreign_lang_name" => null
                            "field_short_name" => null
                            "field_subject_type" => "technical_subject"
                            "field_translit" => "geometrija"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1134
                      #items: array:2 [
                        0 => App\Models\Term {#1135
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [
                            "id" => 5459
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "10"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "desjatyj"
                          ]
                          #original: array:6 [
                            "id" => 5459
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "10"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "desjatyj"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                        1 => App\Models\Term {#1136
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [
                            "id" => 5460
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "11"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "odinadcatyj"
                          ]
                          #original: array:6 [
                            "id" => 5460
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "11"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "odinadcatyj"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1137
                      #items: array:1 [
                        0 => App\Models\Term {#1138
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [
                            "id" => 5153
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Просвещение"
                            "field_cases" => null
                            "field_translit" => "prosveschenie"
                          ]
                          #original: array:6 [
                            "id" => 5153
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Просвещение"
                            "field_cases" => null
                            "field_translit" => "prosveschenie"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1139
                      #items: array:5 [
                        0 => App\Models\Term {#1140
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:12 [
                            "id" => 3753
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Атанасян"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Левон"
                            "field_patronymic" => "Сергеевич"
                            "field_surname_rp" => null
                          ]
                          #original: array:12 [
                            "id" => 3753
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Атанасян"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Левон"
                            "field_patronymic" => "Сергеевич"
                            "field_surname_rp" => null
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                        1 => App\Models\Term {#1141
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:12 [
                            "id" => 3949
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Бутузов"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Валентин"
                            "field_patronymic" => "Фёдорович"
                            "field_surname_rp" => null
                          ]
                          #original: array:12 [
                            "id" => 3949
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Бутузов"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Валентин"
                            "field_patronymic" => "Фёдорович"
                            "field_surname_rp" => null
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                        2 => App\Models\Term {#1142
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:12 [
                            "id" => 4518
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Кадомцев"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Сергей"
                            "field_patronymic" => "Борисович"
                            "field_surname_rp" => null
                          ]
                          #original: array:12 [
                            "id" => 4518
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Кадомцев"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Сергей"
                            "field_patronymic" => "Борисович"
                            "field_surname_rp" => null
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                        3 => App\Models\Term {#1143
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:12 [
                            "id" => 5494
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Позняк"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Эдуард"
                            "field_patronymic" => "Генрихович"
                            "field_surname_rp" => null
                          ]
                          #original: array:12 [
                            "id" => 5494
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Позняк"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Эдуард"
                            "field_patronymic" => "Генрихович"
                            "field_surname_rp" => null
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                        4 => App\Models\Term {#1144
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:12 [
                            "id" => 6905
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Киселёва"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Людмила"
                            "field_patronymic" => "Сергеевна"
                            "field_surname_rp" => null
                          ]
                          #original: array:12 [
                            "id" => 6905
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Киселёва"
                            "field_bio" => null
                            "field_degree_rp" => null
                            "field_foreign_lang_name" => null
                            "field_foreign_lang_patronymic" => null
                            "field_foreign_lang_surname" => null
                            "field_name" => "Людмила"
                            "field_patronymic" => "Сергеевна"
                            "field_surname_rp" => null
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1145
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1146
                      #items: array:1 [
                        0 => App\Models\Term {#1147
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:10 [
                            "id" => 6671
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Учебник"
                            "field_book_type_foreign" => null
                            "field_cases" => array:6 [ …6]
                            "field_plural_form" => null
                            "field_short_name" => null
                            "field_short_name_foreign" => null
                            "field_translit" => "uchebnik"
                          ]
                          #original: array:10 [
                            "id" => 6671
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Учебник"
                            "field_book_type_foreign" => null
                            "field_cases" => array:6 [ …6]
                            "field_plural_form" => null
                            "field_short_name" => null
                            "field_short_name_foreign" => null
                            "field_translit" => "uchebnik"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1148
                      #items: array:1 [
                        0 => App\Models\Term {#1149
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [
                            "id" => 9
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Россия"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "rossiya"
                          ]
                          #original: array:6 [
                            "id" => 9
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Россия"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "rossiya"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [
                            0 => "*"
                          ]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1150
                      #items: array:1 [
                        0 => App\Models\Term {#1151
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [
                            "id" => 15
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Москва"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "moskva"
                          ]
                          #original: array:6 [
                            "id" => 15
                            "created_at" => "2026-04-10 13:58:26"
                            "updated_at" => null
                            "name" => "Москва"
                            "field_cases" => array:6 [ …6]
                            "field_translit" => "moskva"
                          ]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [ …1]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1152
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1153
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1154
                      #items: array:1 [
                        0 => App\Models\Term {#1155
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [ …6]
                          #original: array:6 [ …6]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [ …1]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1156
                      #items: array:1 [
                        0 => App\Models\Term {#1157
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:10 [ …10]
                          #original: array:10 [ …10]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [ …1]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_publication_number" => "11"
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1158
                      #items: array:1 [
                        0 => App\Models\Term {#1159
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [ …6]
                          #original: array:6 [ …6]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [ …1]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1160
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => "с ромбами"
                    "field_publication_year" => "2019"
                    "field_publication_year_until" => null
                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебник для общеобразовательных организаций"
                    "field_allowed" => "Допущено Министерством просвещения Российской Федерации"
                    "field_reserve_field" => "Математика: алгебра и начала математического анализа, геометрия"
                    "field_link_to_source" => null
                    "field_tasks_count" => "1147"
                    "field_priority" => "12"
                    "field_default_folder" => "/geometrija_10/atanasjan-u23/"
                    "field_isbn" => "978-5-09-103606-0 (2023)"
                    "field_cover" => array:1 [
                      0 => "/media/geometrija_10/atanasjan-u23/covers/cover1.webp?ts=1739363242"
                    ]
                    "field_cover_alts" => array:1 [
                      0 => ""
                    ]
                    "field_covers" => array:1 [
                      0 => array:4 [
                        "path" => "/media/geometrija_10/atanasjan-u23/covers/cover1.webp?ts=1739363242"
                        "alt" => ""
                        "width" => "1200"
                        "height" => "1661"
                      ]
                    ]
                    "field_popular_book" => null
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1161
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1162
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1163
                      #items: []
                      #escapeWhenCastingToString: false
                    }
                    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1164
                      #items: array:1 [
                        0 => App\Models\Term {#1165
                          #connection: "mysql"
                          #table: "terms"
                          #primaryKey: "id"
                          #keyType: "int"
                          +incrementing: false
                          #with: []
                          #withCount: []
                          +preventsLazyLoading: false
                          #perPage: 15
                          +exists: true
                          +wasRecentlyCreated: false
                          #escapeWhenCastingToString: false
                          #attributes: array:6 [ …6]
                          #original: array:6 [ …6]
                          #changes: []
                          #casts: []
                          #classCastCache: []
                          #attributeCastCache: []
                          #dateFormat: null
                          #appends: []
                          #dispatchesEvents: []
                          #observables: []
                          #relations: []
                          #touches: []
                          +timestamps: true
                          +usesUniqueIds: false
                          #hidden: []
                          #visible: []
                          #fillable: []
                          #guarded: array:1 [ …1]
                        }
                      ]
                      #escapeWhenCastingToString: false
                    }
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [
                      "class" => 381
                      "subject" => 543
                      "class_subject" => 392
                    ]
                  ]
                  #original: array:50 [
                    "id" => 36
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "field_tree_default_status" => "tasks"
                    "field_pages_status" => null
                    "field_subject" => Illuminate\Database\Eloquent\Collection {#1133}
                    "field_class" => Illuminate\Database\Eloquent\Collection {#1134}
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1137}
                    "field_author" => Illuminate\Database\Eloquent\Collection {#1139}
                    "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1145}
                    "field_book_type" => Illuminate\Database\Eloquent\Collection {#1146}
                    "field_country" => Illuminate\Database\Eloquent\Collection {#1148}
                    "field_city" => Illuminate\Database\Eloquent\Collection {#1150}
                    "field_series" => Illuminate\Database\Eloquent\Collection {#1152}
                    "field_umk" => Illuminate\Database\Eloquent\Collection {#1153}
                    "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1154}
                    "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1156}
                    "field_publication_number" => "11"
                    "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1158}
                    "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1160}
                    "field_under_the_edition_degree" => null
                    "field_cover_description" => "с ромбами"
                    "field_publication_year" => "2019"
                    "field_publication_year_until" => null
                    "field_part" => ""
                    "field_part_writing" => ""
                    "field_second_foreign_language" => null
                    "field_for_whom" => "Учебник для общеобразовательных организаций"
                    "field_allowed" => "Допущено Министерством просвещения Российской Федерации"
                    "field_reserve_field" => "Математика: алгебра и начала математического анализа, геометрия"
                    "field_link_to_source" => null
                    "field_tasks_count" => "1147"
                    "field_priority" => "12"
                    "field_default_folder" => "/geometrija_10/atanasjan-u23/"
                    "field_isbn" => "978-5-09-103606-0 (2023)"
                    "field_cover" => array:1 [
                      0 => "/media/geometrija_10/atanasjan-u23/covers/cover1.webp?ts=1739363242"
                    ]
                    "field_cover_alts" => array:1 [
                      0 => ""
                    ]
                    "field_covers" => array:1 [
                      0 => array:4 [
                        "path" => "/media/geometrija_10/atanasjan-u23/covers/cover1.webp?ts=1739363242"
                        "alt" => ""
                        "width" => "1200"
                        "height" => "1661"
                      ]
                    ]
                    "field_popular_book" => null
                    "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1161}
                    "field_new_book" => Illuminate\Database\Eloquent\Collection {#1162}
                    "field_old_book" => Illuminate\Database\Eloquent\Collection {#1163}
                    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik"
                    "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1164}
                    "field_metatags_title" => null
                    "field_metatags_description" => null
                    "field_h1" => null
                    "field_description_top" => null
                    "field_description_bottom" => null
                    "breadcrumbs" => array:3 [
                      "class" => 381
                      "subject" => 543
                      "class_subject" => 392
                    ]
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1166
              #items: []
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 744405
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Метод координат в пространстве. Движения"
            "field_branch_order" => "7"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1132}
            "field_page_start" => "160"
            "field_branch_display" => "0"
            "field_branch_expanded" => "0"
            "field_display_branch_in_title" => "1"
            "field_display_task_interval" => "0"
            "field_display_branch_page" => "1"
            "field_branch_title_in_content" => "0"
            "field_navigation_title" => null
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1168}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1166}
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        1 => App\Models\Branch {#1167
          #connection: "mysql"
          #table: "branches"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:24 [
            "id" => 744410
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Движения, дополнительные задачи"
            "field_branch_order" => "3"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1172
              #items: array:1 [
                0 => App\Models\Term {#1169
                  #connection: "mysql"
                  #table: "terms"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:7 [
                    "id" => 32
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Параграф"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => "§"
                  ]
                  #original: array:7 [
                    "id" => 32
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "name" => "Параграф"
                    "field_cases" => array:6 [ …6]
                    "field_page_check_not_needed" => null
                    "field_short_name" => "§"
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "187"
            "field_branch_display" => "0"
            "field_branch_expanded" => "0"
            "field_display_branch_in_title" => "1"
            "field_display_task_interval" => "0"
            "field_display_branch_page" => "1"
            "field_branch_title_in_content" => "0"
            "field_navigation_title" => null
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1171
              #items: array:1 [
                0 => App\Models\Book {#1131}
              ]
              #escapeWhenCastingToString: false
            }
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1170
              #items: array:1 [
                0 => App\Models\Branch {#1034}
              ]
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:24 [
            "id" => 744410
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Движения, дополнительные задачи"
            "field_branch_order" => "3"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1172}
            "field_page_start" => "187"
            "field_branch_display" => "0"
            "field_branch_expanded" => "0"
            "field_display_branch_in_title" => "1"
            "field_display_task_interval" => "0"
            "field_display_branch_page" => "1"
            "field_branch_title_in_content" => "0"
            "field_navigation_title" => null
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "field_branch_cover" => []
            "field_branch_covers" => []
            "book" => Illuminate\Database\Eloquent\Collection {#1171}
            "branch_parent" => Illuminate\Database\Eloquent\Collection {#1170}
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "content" => Illuminate\Database\Eloquent\Collection {#1117
      #items: array:3 [
        0 => App\Models\Element {#1109
          #connection: "mysql"
          #table: "elements"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:7 [
            "id" => 939878
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1102
              #items: array:1 [
                0 => App\Models\Edition {#1110
                  #connection: "mysql"
                  #table: "editions"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:21 [
                    "id" => 2315
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Условие"
                    "field_order" => "1"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1108 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "text, image"
                    "field_page_content_mode" => "image"
                    "field_content_text_checked" => null
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Автор"
                    "field_moderator" => "pasha"
                    "field_edition_type" => "statement"
                    "field_root_dir" => "0-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1105 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1106 …2}
                    "field_process_formula" => "wiris"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1104 …2}
                    "field_content_source" => null
                  ]
                  #original: array:21 [
                    "id" => 2315
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Условие"
                    "field_order" => "1"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1108 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "text, image"
                    "field_page_content_mode" => "image"
                    "field_content_text_checked" => null
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Автор"
                    "field_moderator" => "pasha"
                    "field_edition_type" => "statement"
                    "field_root_dir" => "0-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1105 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1106 …2}
                    "field_process_formula" => "wiris"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1104 …2}
                    "field_content_source" => null
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "745190"
              "type" => "task"
            ]
            "text" => "<p> <b>775</b>. Докажите, что сумма квадратов расстояний от вершин куба до прямой, проходящей через его центр, не зависит от положения этой прямой. </p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "775-1.jpg"
                "alt" => null
                "width" => "1569"
                "height" => 202
                "path" => "/media/geometrija_10/atanasjan-u23/0-00/775-1.webp?ts=1739436882"
              ]
            ]
          ]
          #original: array:7 [
            "id" => 939878
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1102}
            "task" => array:2 [
              "refs" => "745190"
              "type" => "task"
            ]
            "text" => "<p> <b>775</b>. Докажите, что сумма квадратов расстояний от вершин куба до прямой, проходящей через его центр, не зависит от положения этой прямой. </p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "775-1.jpg"
                "alt" => null
                "width" => "1569"
                "height" => 202
                "path" => "/media/geometrija_10/atanasjan-u23/0-00/775-1.webp?ts=1739436882"
              ]
            ]
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        1 => App\Models\Element {#1103
          #connection: "mysql"
          #table: "elements"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:6 [
            "id" => 942736
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1094
              #items: array:1 [
                0 => App\Models\Edition {#1101
                  #connection: "mysql"
                  #table: "editions"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:21 [
                    "id" => 2317
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 2"
                    "field_order" => "3"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1100 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "image"
                    "field_page_content_mode" => ""
                    "field_content_text_checked" => "0"
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Неизвестный"
                    "field_moderator" => "pasha"
                    "field_edition_type" => "solution"
                    "field_root_dir" => "2-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1097 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1098 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1096 …2}
                    "field_content_source" => null
                  ]
                  #original: array:21 [
                    "id" => 2317
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 2"
                    "field_order" => "3"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1100 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "image"
                    "field_page_content_mode" => ""
                    "field_content_text_checked" => "0"
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Неизвестный"
                    "field_moderator" => "pasha"
                    "field_edition_type" => "solution"
                    "field_root_dir" => "2-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1097 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1098 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1096 …2}
                    "field_content_source" => null
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "745190"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "775-1.png"
                "alt" => null
                "width" => "694"
                "height" => 7095
                "path" => "/media/geometrija_10/atanasjan-u23/2-00/775-1.webp?ts=1739441669"
              ]
            ]
          ]
          #original: array:6 [
            "id" => 942736
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1094}
            "task" => array:2 [
              "refs" => "745190"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "775-1.png"
                "alt" => null
                "width" => "694"
                "height" => 7095
                "path" => "/media/geometrija_10/atanasjan-u23/2-00/775-1.webp?ts=1739441669"
              ]
            ]
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        2 => App\Models\Element {#1090
          #connection: "mysql"
          #table: "elements"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:6 [
            "id" => 1352503
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1086
              #items: array:1 [
                0 => App\Models\Edition {#1095
                  #connection: "mysql"
                  #table: "editions"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: false
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:21 [
                    "id" => 5120
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 6"
                    "field_order" => "7"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1092 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "text"
                    "field_page_content_mode" => ""
                    "field_content_text_checked" => null
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Gemini 2.5 Pro"
                    "field_moderator" => "vadim"
                    "field_edition_type" => "solution"
                    "field_root_dir" => "6-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1091 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1088 …2}
                    "field_process_formula" => "katex"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1089 …2}
                    "field_content_source" => null
                  ]
                  #original: array:21 [
                    "id" => 5120
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 6"
                    "field_order" => "7"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1092 …2}
                    "field_content_type" => "free"
                    "field_content_mode" => "text"
                    "field_page_content_mode" => ""
                    "field_content_text_checked" => null
                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Gemini 2.5 Pro"
                    "field_moderator" => "vadim"
                    "field_edition_type" => "solution"
                    "field_root_dir" => "6-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1091 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1088 …2}
                    "field_process_formula" => "katex"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1089 …2}
                    "field_content_source" => null
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "745190"
              "type" => "task"
            ]
            "text" => "<p>Для доказательства воспользуемся методом координат. Пусть ребро куба имеет длину $L$. Разместим центр куба в начале координат $O(0, 0, 0)$. Тогда оси координат можно направить параллельно ребрам куба. В этой системе координат вершины куба будут иметь следующие координаты:</p><p>$V_i = (\pm \frac{L}{2}, \pm \frac{L}{2}, \pm \frac{L}{2})$</p><p>Всего у куба 8 вершин. Обозначим радиус-векторы вершин как $\vec{v_i}$. Квадрат расстояния от начала координат до любой вершины одинаков и равен:</p><p>$|\vec{v_i}|^2 = (\pm \frac{L}{2})^2 + (\pm \frac{L}{2})^2 + (\pm \frac{L}{2})^2 = \frac{L^2}{4} + \frac{L^2}{4} + \frac{L^2}{4} = \frac{3L^2}{4}$</p><p>Рассмотрим произвольную прямую, проходящую через центр куба (начало координат). Положение такой прямой в пространстве однозначно задается ее направляющим вектором. Пусть это будет единичный вектор $\vec{u} = (l, m, n)$, где $l, m, n$ - его направляющие косинусы. Для единичного вектора выполняется условие: $l^2 + m^2 + n^2 = 1$.</p><p>Расстояние $d_i$ от точки (вершины) с радиус-вектором $\vec{v_i}$ до прямой, проходящей через начало координат с направляющим вектором $\vec{u}$, можно найти по формуле для высоты параллелограмма, построенного на векторах $\vec{v_i}$ и $\vec{u}$:</p><p>$d_i = \frac{|\vec{v_i} \times \vec{u}|}{|\vec{u}|}$</p><p>Так как мы выбрали $|\vec{u}| = 1$, квадрат расстояния равен:</p><p>$d_i^2 = |\vec{v_i} \times \vec{u}|^2$</p><p>Используя известное тождество для векторного произведения $|\vec{a} \times \vec{b}|^2 = |\vec{a}|^2|\vec{b}|^2 - (\vec{a} \cdot \vec{b})^2$, получим:</p><p>$d_i^2 = |\vec{v_i}|^2|\vec{u}|^2 - (\vec{v_i} \cdot \vec{u})^2 = |\vec{v_i}|^2 - (\vec{v_i} \cdot \vec{u})^2$</p><p>Нам нужно доказать, что сумма квадратов этих расстояний для всех 8 вершин не зависит от выбора прямой, то есть от вектора $\vec{u}$. Найдем эту сумму $S$:</p><p>$S = \sum_{i=1}^{8} d_i^2 = \sum_{i=1}^{8} (|\vec{v_i}|^2 - (\vec{v_i} \cdot \vec{u})^2) = \sum_{i=1}^{8} |\vec{v_i}|^2 - \sum_{i=1}^{8} (\vec{v_i} \cdot \vec{u})^2$</p><p>Вычислим каждую из сумм по отдельности.</p><p>1. Первая сумма:</p><p>$\sum_{i=1}^{8} |\vec{v_i}|^2 = \sum_{i=1}^{8} \frac{3L^2}{4} = 8 \cdot \frac{3L^2}{4} = 6L^2$</p><p>2. Вторая сумма:</p><p>Пусть координаты вершины $V_i$ - это $(x_i, y_i, z_i)$, где каждое из $x_i, y_i, z_i$ равно либо $+\frac{L}{2}$, либо $-\frac{L}{2}$.</p><p>$\vec{v_i} \cdot \vec{u} = x_i l + y_i m + z_i n$</p><p>$(\vec{v_i} \cdot \vec{u})^2 = (x_i l + y_i m + z_i n)^2 = x_i^2 l^2 + y_i^2 m^2 + z_i^2 n^2 + 2x_i y_i lm + 2x_i z_i ln + 2y_i z_i mn$</p><p>Просуммируем это выражение по всем 8 вершинам. Для любой вершины $x_i^2 = y_i^2 = z_i^2 = (\frac{L}{2})^2 = \frac{L^2}{4}$.</p><p>$\sum_{i=1}^{8} (x_i^2 l^2 + y_i^2 m^2 + z_i^2 n^2) = \sum_{i=1}^{8} (\frac{L^2}{4} l^2 + \frac{L^2}{4} m^2 + \frac{L^2}{4} n^2) = 8 \cdot \frac{L^2}{4} (l^2+m^2+n^2) = 2L^2 \cdot 1 = 2L^2$</p><p>Теперь рассмотрим суммы смешанных произведений. В силу симметрии куба, для каждой вершины $(x_i, y_i, z_i)$ найдется вершина с координатами $(-x_i, y_i, z_i)$, $(x_i, -y_i, z_i)$ и т.д. Например, для суммы $\sum_{i=1}^{8} x_i y_i$: на 8 вершин приходится 4 вершины, где $x_i$ и $y_i$ одного знака (произведение $x_i y_i = \frac{L^2}{4}$), и 4 вершины, где они разных знаков (произведение $x_i y_i = -\frac{L^2}{4}$). Таким образом:</p><p>$\sum_{i=1}^{8} x_i y_i = 4 \cdot (\frac{L^2}{4}) + 4 \cdot (-\frac{L^2}{4}) = 0$</p><p>Аналогично, $\sum_{i=1}^{8} x_i z_i = 0$ и $\sum_{i=1}^{8} y_i z_i = 0$.</p><p>Следовательно, сумма вторых слагаемых равна:</p><p>$\sum_{i=1}^{8} (\vec{v_i} \cdot \vec{u})^2 = 2L^2$</p><p>Теперь мы можем найти итоговую сумму $S$:</p><p>$S = 6L^2 - 2L^2 = 4L^2$</p><p>Полученный результат $4L^2$ зависит только от длины ребра куба $L$ и не зависит от направляющих косинусов $l, m, n$, которые определяют положение прямой в пространстве. Таким образом, мы доказали, что сумма квадратов расстояний от вершин куба до прямой, проходящей через его центр, не зависит от положения этой прямой.</p><p><strong>Ответ:</strong> Доказано. Сумма квадратов расстояний не зависит от положения прямой и равна $4L^2$, где $L$ - длина ребра куба.</p>"
          ]
          #original: array:6 [
            "id" => 1352503
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1086}
            "task" => array:2 [
              "refs" => "745190"
              "type" => "task"
            ]
            "text" => "<p>Для доказательства воспользуемся методом координат. Пусть ребро куба имеет длину $L$. Разместим центр куба в начале координат $O(0, 0, 0)$. Тогда оси координат можно направить параллельно ребрам куба. В этой системе координат вершины куба будут иметь следующие координаты:</p><p>$V_i = (\pm \frac{L}{2}, \pm \frac{L}{2}, \pm \frac{L}{2})$</p><p>Всего у куба 8 вершин. Обозначим радиус-векторы вершин как $\vec{v_i}$. Квадрат расстояния от начала координат до любой вершины одинаков и равен:</p><p>$|\vec{v_i}|^2 = (\pm \frac{L}{2})^2 + (\pm \frac{L}{2})^2 + (\pm \frac{L}{2})^2 = \frac{L^2}{4} + \frac{L^2}{4} + \frac{L^2}{4} = \frac{3L^2}{4}$</p><p>Рассмотрим произвольную прямую, проходящую через центр куба (начало координат). Положение такой прямой в пространстве однозначно задается ее направляющим вектором. Пусть это будет единичный вектор $\vec{u} = (l, m, n)$, где $l, m, n$ - его направляющие косинусы. Для единичного вектора выполняется условие: $l^2 + m^2 + n^2 = 1$.</p><p>Расстояние $d_i$ от точки (вершины) с радиус-вектором $\vec{v_i}$ до прямой, проходящей через начало координат с направляющим вектором $\vec{u}$, можно найти по формуле для высоты параллелограмма, построенного на векторах $\vec{v_i}$ и $\vec{u}$:</p><p>$d_i = \frac{|\vec{v_i} \times \vec{u}|}{|\vec{u}|}$</p><p>Так как мы выбрали $|\vec{u}| = 1$, квадрат расстояния равен:</p><p>$d_i^2 = |\vec{v_i} \times \vec{u}|^2$</p><p>Используя известное тождество для векторного произведения $|\vec{a} \times \vec{b}|^2 = |\vec{a}|^2|\vec{b}|^2 - (\vec{a} \cdot \vec{b})^2$, получим:</p><p>$d_i^2 = |\vec{v_i}|^2|\vec{u}|^2 - (\vec{v_i} \cdot \vec{u})^2 = |\vec{v_i}|^2 - (\vec{v_i} \cdot \vec{u})^2$</p><p>Нам нужно доказать, что сумма квадратов этих расстояний для всех 8 вершин не зависит от выбора прямой, то есть от вектора $\vec{u}$. Найдем эту сумму $S$:</p><p>$S = \sum_{i=1}^{8} d_i^2 = \sum_{i=1}^{8} (|\vec{v_i}|^2 - (\vec{v_i} \cdot \vec{u})^2) = \sum_{i=1}^{8} |\vec{v_i}|^2 - \sum_{i=1}^{8} (\vec{v_i} \cdot \vec{u})^2$</p><p>Вычислим каждую из сумм по отдельности.</p><p>1. Первая сумма:</p><p>$\sum_{i=1}^{8} |\vec{v_i}|^2 = \sum_{i=1}^{8} \frac{3L^2}{4} = 8 \cdot \frac{3L^2}{4} = 6L^2$</p><p>2. Вторая сумма:</p><p>Пусть координаты вершины $V_i$ - это $(x_i, y_i, z_i)$, где каждое из $x_i, y_i, z_i$ равно либо $+\frac{L}{2}$, либо $-\frac{L}{2}$.</p><p>$\vec{v_i} \cdot \vec{u} = x_i l + y_i m + z_i n$</p><p>$(\vec{v_i} \cdot \vec{u})^2 = (x_i l + y_i m + z_i n)^2 = x_i^2 l^2 + y_i^2 m^2 + z_i^2 n^2 + 2x_i y_i lm + 2x_i z_i ln + 2y_i z_i mn$</p><p>Просуммируем это выражение по всем 8 вершинам. Для любой вершины $x_i^2 = y_i^2 = z_i^2 = (\frac{L}{2})^2 = \frac{L^2}{4}$.</p><p>$\sum_{i=1}^{8} (x_i^2 l^2 + y_i^2 m^2 + z_i^2 n^2) = \sum_{i=1}^{8} (\frac{L^2}{4} l^2 + \frac{L^2}{4} m^2 + \frac{L^2}{4} n^2) = 8 \cdot \frac{L^2}{4} (l^2+m^2+n^2) = 2L^2 \cdot 1 = 2L^2$</p><p>Теперь рассмотрим суммы смешанных произведений. В силу симметрии куба, для каждой вершины $(x_i, y_i, z_i)$ найдется вершина с координатами $(-x_i, y_i, z_i)$, $(x_i, -y_i, z_i)$ и т.д. Например, для суммы $\sum_{i=1}^{8} x_i y_i$: на 8 вершин приходится 4 вершины, где $x_i$ и $y_i$ одного знака (произведение $x_i y_i = \frac{L^2}{4}$), и 4 вершины, где они разных знаков (произведение $x_i y_i = -\frac{L^2}{4}$). Таким образом:</p><p>$\sum_{i=1}^{8} x_i y_i = 4 \cdot (\frac{L^2}{4}) + 4 \cdot (-\frac{L^2}{4}) = 0$</p><p>Аналогично, $\sum_{i=1}^{8} x_i z_i = 0$ и $\sum_{i=1}^{8} y_i z_i = 0$.</p><p>Следовательно, сумма вторых слагаемых равна:</p><p>$\sum_{i=1}^{8} (\vec{v_i} \cdot \vec{u})^2 = 2L^2$</p><p>Теперь мы можем найти итоговую сумму $S$:</p><p>$S = 6L^2 - 2L^2 = 4L^2$</p><p>Полученный результат $4L^2$ зависит только от длины ребра куба $L$ и не зависит от направляющих косинусов $l, m, n$, которые определяют положение прямой в пространстве. Таким образом, мы доказали, что сумма квадратов расстояний от вершин куба до прямой, проходящей через его центр, не зависит от положения этой прямой.</p><p><strong>Ответ:</strong> Доказано. Сумма квадратов расстояний не зависит от положения прямой и равна $4L^2$, где $L$ - длина ребра куба.</p>"
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
    "next" => array:2 [
      "refs" => "745191"
      "type" => "task"
    ]
    "previous" => array:2 [
      "refs" => "745189"
      "type" => "task"
    ]
    "book" => Illuminate\Database\Eloquent\Collection {#1113
      #items: array:1 [
        0 => App\Models\Book {#1131}
      ]
      #escapeWhenCastingToString: false
    }
    "page" => Illuminate\Database\Eloquent\Collection {#1116
      #items: array:1 [
        0 => App\Models\BookPage {#1081
          #connection: "mysql"
          #table: "book_pages"
          #primaryKey: "id"
          #keyType: "int"
          +incrementing: true
          #with: []
          #withCount: []
          +preventsLazyLoading: false
          #perPage: 15
          +exists: true
          +wasRecentlyCreated: false
          #escapeWhenCastingToString: false
          #attributes: array:21 [
            "id" => 933972
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_page_start" => "190"
            "field_url" => "/10-klass/geometrija/atanasjan-uchebnik/page-190"
            "field_display_title" => "190"
            "field_folder" => "1"
            "field_image_name" => "190"
            "field_branch_parent" => Illuminate\Database\Eloquent\Collection {#1082
              #items: []
              #escapeWhenCastingToString: false
            }
            "field_weight" => "0"
            "field_book_parent" => Illuminate\Database\Eloquent\Collection {#1085
              #items: array:1 [
                0 => App\Models\Book {#1131}
              ]
              #escapeWhenCastingToString: false
            }
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "edition_groups" => Illuminate\Database\Eloquent\Collection {#1087
              #items: []
              #escapeWhenCastingToString: false
            }
            "content" => Illuminate\Database\Eloquent\Collection {#1124
              #items: array:1 [
                0 => App\Models\Element {#1121
                  #connection: "mysql"
                  #table: "elements"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:6 [ …6]
                  #original: array:6 [ …6]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "next" => array:2 [
              "refs" => "933973"
              "type" => "book_page"
            ]
            "previous" => array:2 [
              "refs" => "933971"
              "type" => "book_page"
            ]
            "tasks" => Illuminate\Database\Eloquent\Collection {#1284
              #items: array:13 [
                0 => App\Models\Task {#1304
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                1 => App\Models\Task {#1311
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                2 => App\Models\Task {#1312
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                3 => App\Models\Task {#1337
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                4 => App\Models\Task {#1349
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                5 => App\Models\Task {#1362
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                6 => App\Models\Task {#1381
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                7 => App\Models\Task {#1395
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                8 => App\Models\Task {#1407
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                9 => App\Models\Task {#1425
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                10 => App\Models\Task {#1430
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                11 => App\Models\Task {#1444
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
                12 => App\Models\Task {#1458
                  #connection: "mysql"
                  #table: "tasks"
                  #primaryKey: "id"
                  #keyType: "int"
                  +incrementing: true
                  #with: []
                  #withCount: []
                  +preventsLazyLoading: false
                  #perPage: 15
                  +exists: true
                  +wasRecentlyCreated: false
                  #escapeWhenCastingToString: false
                  #attributes: array:24 [ …24]
                  #original: array:24 [ …24]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
                  #relations: []
                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
          ]
          #original: array:21 [
            "id" => 933972
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_page_start" => "190"
            "field_url" => "/10-klass/geometrija/atanasjan-uchebnik/page-190"
            "field_display_title" => "190"
            "field_folder" => "1"
            "field_image_name" => "190"
            "field_branch_parent" => Illuminate\Database\Eloquent\Collection {#1082}
            "field_weight" => "0"
            "field_book_parent" => Illuminate\Database\Eloquent\Collection {#1085}
            "field_metatags_title" => null
            "field_metatags_description" => null
            "field_h1" => null
            "field_description_top" => null
            "field_description_bottom" => null
            "edition_groups" => Illuminate\Database\Eloquent\Collection {#1087}
            "content" => Illuminate\Database\Eloquent\Collection {#1124}
            "next" => array:2 [
              "refs" => "933973"
              "type" => "book_page"
            ]
            "previous" => array:2 [
              "refs" => "933971"
              "type" => "book_page"
            ]
            "tasks" => Illuminate\Database\Eloquent\Collection {#1284}
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
          #observables: []
          #relations: []
          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
      ]
      #escapeWhenCastingToString: false
    }
  ]
  #original: array:24 [
    "id" => 745190
    "created_at" => "2026-04-10 13:58:26"
    "updated_at" => null
    "field_page_start" => "190"
    "field_page_end" => null
    "field_url" => "/10-klass/geometrija/atanasjan-uchebnik/00-775"
    "field_display_title" => "775"
    "field_outside_task" => null
    "field_task_type" => Illuminate\Database\Eloquent\Collection {#1037}
    "field_metatags_title" => null
    "field_metatags_description" => null
    "field_h1" => null
    "field_description_top" => null
    "field_description_bottom" => null
    "field_match" => null
    "breadcrumbs" => []
    "edition_groups" => Illuminate\Database\Eloquent\Collection {#1035}
    "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1079}
    "parent_branches" => Illuminate\Database\Eloquent\Collection {#1120}
    "content" => Illuminate\Database\Eloquent\Collection {#1117}
    "next" => array:2 [
      "refs" => "745191"
      "type" => "task"
    ]
    "previous" => array:2 [
      "refs" => "745189"
      "type" => "task"
    ]
    "book" => Illuminate\Database\Eloquent\Collection {#1113}
    "page" => array:2 [
      "refs" => "933972"
      "type" => "book_page"
    ]
  ]
  #changes: []
  #casts: []
  #classCastCache: []
  #attributeCastCache: []
  #dateFormat: null
  #appends: []
  #dispatchesEvents: []
  #observables: []
  #relations: []
  #touches: []
  +timestamps: true
  +usesUniqueIds: false
  #hidden: []
  #visible: []
  #fillable: []
  #guarded: array:1 [
    0 => "*"
  ]
}
№775 (с. 190)
Условие. №775 (с. 190)
скриншот условия
Геометрия, 10-11 класс Учебник, авторы: Атанасян Левон Сергеевич, Бутузов Валентин Фёдорович, Кадомцев Сергей Борисович, Позняк Эдуард Генрихович, Киселёва Людмила Сергеевна, издательство Просвещение, Москва, 2019, коричневого цвета, страница 190, номер 775, Условие

775. Докажите, что сумма квадратов расстояний от вершин куба до прямой, проходящей через его центр, не зависит от положения этой прямой.

Решение 2. №775 (с. 190)
Геометрия, 10-11 класс Учебник, авторы: Атанасян Левон Сергеевич, Бутузов Валентин Фёдорович, Кадомцев Сергей Борисович, Позняк Эдуард Генрихович, Киселёва Людмила Сергеевна, издательство Просвещение, Москва, 2019, коричневого цвета, страница 190, номер 775, Решение 2
Решение 6. №775 (с. 190)

Для доказательства воспользуемся методом координат. Пусть ребро куба имеет длину $L$. Разместим центр куба в начале координат $O(0, 0, 0)$. Тогда оси координат можно направить параллельно ребрам куба. В этой системе координат вершины куба будут иметь следующие координаты:

$V_i = (\pm \frac{L}{2}, \pm \frac{L}{2}, \pm \frac{L}{2})$

Всего у куба 8 вершин. Обозначим радиус-векторы вершин как $\vec{v_i}$. Квадрат расстояния от начала координат до любой вершины одинаков и равен:

$|\vec{v_i}|^2 = (\pm \frac{L}{2})^2 + (\pm \frac{L}{2})^2 + (\pm \frac{L}{2})^2 = \frac{L^2}{4} + \frac{L^2}{4} + \frac{L^2}{4} = \frac{3L^2}{4}$

Рассмотрим произвольную прямую, проходящую через центр куба (начало координат). Положение такой прямой в пространстве однозначно задается ее направляющим вектором. Пусть это будет единичный вектор $\vec{u} = (l, m, n)$, где $l, m, n$ - его направляющие косинусы. Для единичного вектора выполняется условие: $l^2 + m^2 + n^2 = 1$.

Расстояние $d_i$ от точки (вершины) с радиус-вектором $\vec{v_i}$ до прямой, проходящей через начало координат с направляющим вектором $\vec{u}$, можно найти по формуле для высоты параллелограмма, построенного на векторах $\vec{v_i}$ и $\vec{u}$:

$d_i = \frac{|\vec{v_i} \times \vec{u}|}{|\vec{u}|}$

Так как мы выбрали $|\vec{u}| = 1$, квадрат расстояния равен:

$d_i^2 = |\vec{v_i} \times \vec{u}|^2$

Используя известное тождество для векторного произведения $|\vec{a} \times \vec{b}|^2 = |\vec{a}|^2|\vec{b}|^2 - (\vec{a} \cdot \vec{b})^2$, получим:

$d_i^2 = |\vec{v_i}|^2|\vec{u}|^2 - (\vec{v_i} \cdot \vec{u})^2 = |\vec{v_i}|^2 - (\vec{v_i} \cdot \vec{u})^2$

Нам нужно доказать, что сумма квадратов этих расстояний для всех 8 вершин не зависит от выбора прямой, то есть от вектора $\vec{u}$. Найдем эту сумму $S$:

$S = \sum_{i=1}^{8} d_i^2 = \sum_{i=1}^{8} (|\vec{v_i}|^2 - (\vec{v_i} \cdot \vec{u})^2) = \sum_{i=1}^{8} |\vec{v_i}|^2 - \sum_{i=1}^{8} (\vec{v_i} \cdot \vec{u})^2$

Вычислим каждую из сумм по отдельности.

1. Первая сумма:

$\sum_{i=1}^{8} |\vec{v_i}|^2 = \sum_{i=1}^{8} \frac{3L^2}{4} = 8 \cdot \frac{3L^2}{4} = 6L^2$

2. Вторая сумма:

Пусть координаты вершины $V_i$ - это $(x_i, y_i, z_i)$, где каждое из $x_i, y_i, z_i$ равно либо $+\frac{L}{2}$, либо $-\frac{L}{2}$.

$\vec{v_i} \cdot \vec{u} = x_i l + y_i m + z_i n$

$(\vec{v_i} \cdot \vec{u})^2 = (x_i l + y_i m + z_i n)^2 = x_i^2 l^2 + y_i^2 m^2 + z_i^2 n^2 + 2x_i y_i lm + 2x_i z_i ln + 2y_i z_i mn$

Просуммируем это выражение по всем 8 вершинам. Для любой вершины $x_i^2 = y_i^2 = z_i^2 = (\frac{L}{2})^2 = \frac{L^2}{4}$.

$\sum_{i=1}^{8} (x_i^2 l^2 + y_i^2 m^2 + z_i^2 n^2) = \sum_{i=1}^{8} (\frac{L^2}{4} l^2 + \frac{L^2}{4} m^2 + \frac{L^2}{4} n^2) = 8 \cdot \frac{L^2}{4} (l^2+m^2+n^2) = 2L^2 \cdot 1 = 2L^2$

Теперь рассмотрим суммы смешанных произведений. В силу симметрии куба, для каждой вершины $(x_i, y_i, z_i)$ найдется вершина с координатами $(-x_i, y_i, z_i)$, $(x_i, -y_i, z_i)$ и т.д. Например, для суммы $\sum_{i=1}^{8} x_i y_i$: на 8 вершин приходится 4 вершины, где $x_i$ и $y_i$ одного знака (произведение $x_i y_i = \frac{L^2}{4}$), и 4 вершины, где они разных знаков (произведение $x_i y_i = -\frac{L^2}{4}$). Таким образом:

$\sum_{i=1}^{8} x_i y_i = 4 \cdot (\frac{L^2}{4}) + 4 \cdot (-\frac{L^2}{4}) = 0$

Аналогично, $\sum_{i=1}^{8} x_i z_i = 0$ и $\sum_{i=1}^{8} y_i z_i = 0$.

Следовательно, сумма вторых слагаемых равна:

$\sum_{i=1}^{8} (\vec{v_i} \cdot \vec{u})^2 = 2L^2$

Теперь мы можем найти итоговую сумму $S$:

$S = 6L^2 - 2L^2 = 4L^2$

Полученный результат $4L^2$ зависит только от длины ребра куба $L$ и не зависит от направляющих косинусов $l, m, n$, которые определяют положение прямой в пространстве. Таким образом, мы доказали, что сумма квадратов расстояний от вершин куба до прямой, проходящей через его центр, не зависит от положения этой прямой.

Ответ: Доказано. Сумма квадратов расстояний не зависит от положения прямой и равна $4L^2$, где $L$ - длина ребра куба.

Помогло решение? Оставьте отзыв в комментариях ниже.

Присоединяйтесь к Телеграм-группе @top_gdz

Присоединиться

Мы подготовили для вас ответ c подробным объяснением домашего задания по геометрии за 10-11 класс, для упражнения номер 775 расположенного на странице 190 к учебнику 2019 года издания для учащихся школ и гимназий.

Теперь на нашем сайте ГДЗ.ТОП вы всегда легко и бесплатно найдёте условие с правильным ответом на вопрос «Как решить ДЗ» и «Как сделать» задание по геометрии к упражнению №775 (с. 190), авторов: Атанасян (Левон Сергеевич), Бутузов (Валентин Фёдорович), Кадомцев (Сергей Борисович), Позняк (Эдуард Генрихович), Киселёва (Людмила Сергеевна), ФГОС (старый) базовый и углублённый уровень обучения учебного пособия издательства Просвещение.