Номер 716, страница 179 - 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 2. Скалярное произведение векторов - номер 716, страница 179.

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                          #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_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 [ …12]
                          #original: array:12 [ …12]
                          #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\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 [ …12]
                          #original: array:12 [ …12]
                          #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\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 [ …12]
                          #original: array:12 [ …12]
                          #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\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 [ …12]
                          #original: array:12 [ …12]
                          #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\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 [ …12]
                          #original: array:12 [ …12]
                          #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_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 [ …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_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 [ …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_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 [ …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_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" => 744407
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Скалярное произведение векторов"
            "field_branch_order" => "2"
            "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
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                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [
                    0 => "*"
                  ]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "field_page_start" => "171"
            "field_branch_display" => "0"
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            "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" => 744407
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "field_display_title" => "Скалярное произведение векторов"
            "field_branch_order" => "2"
            "field_url" => null
            "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1172}
            "field_page_start" => "171"
            "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:5 [
        0 => App\Models\Element {#1107
          #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" => 939624
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1100
              #items: array:1 [
                0 => App\Models\Edition {#1108
                  #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 {#1106 …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 {#1104 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1103 …2}
                    "field_process_formula" => "wiris"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1101 …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 {#1106 …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 {#1104 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1103 …2}
                    "field_process_formula" => "wiris"
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1101 …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" => "745131"
              "type" => "task"
            ]
            "text" => "<p> <b>716.</b> В тетраэдре DABC <span class="long">DA = 5 см,</span> <span class="long">AB = 4 см,</span> <span class="long">АС = 3 см,</span> <span class="long">∠BAC = 90°,</span> <span class="long">∠DAB = 60°,</span> <span class="long">∠DAC = 45°.</span> Найдите расстояние от вершины <i>А</i> до точки пересечения медиан треугольника <i>DBC.</i> </p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "716-1.jpg"
                "alt" => null
                "width" => "1562"
                "height" => 230
                "path" => "/media/geometrija_10/atanasjan-u23/0-00/716-1.webp?ts=1739436846"
              ]
            ]
          ]
          #original: array:7 [
            "id" => 939624
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1100}
            "task" => array:2 [
              "refs" => "745131"
              "type" => "task"
            ]
            "text" => "<p> <b>716.</b> В тетраэдре DABC <span class="long">DA = 5 см,</span> <span class="long">AB = 4 см,</span> <span class="long">АС = 3 см,</span> <span class="long">∠BAC = 90°,</span> <span class="long">∠DAB = 60°,</span> <span class="long">∠DAC = 45°.</span> Найдите расстояние от вершины <i>А</i> до точки пересечения медиан треугольника <i>DBC.</i> </p>"
            "img" => array:1 [
              0 => array:5 [
                "name" => "716-1.jpg"
                "alt" => null
                "width" => "1562"
                "height" => 230
                "path" => "/media/geometrija_10/atanasjan-u23/0-00/716-1.webp?ts=1739436846"
              ]
            ]
          ]
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          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
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          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        1 => App\Models\Element {#1086
          #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" => 942591
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1124
              #items: array:1 [
                0 => App\Models\Edition {#1083
                  #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 {#1078 …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 {#1119 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1118 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1127 …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 {#1078 …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 {#1119 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1118 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1127 …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" => "745131"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "716-1.png"
                "alt" => null
                "width" => "694"
                "height" => 8070
                "path" => "/media/geometrija_10/atanasjan-u23/2-00/716-1.webp?ts=1739441614"
              ]
            ]
          ]
          #original: array:6 [
            "id" => 942591
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1124}
            "task" => array:2 [
              "refs" => "745131"
              "type" => "task"
            ]
            "img" => array:1 [
              0 => array:5 [
                "name" => "716-1.png"
                "alt" => null
                "width" => "694"
                "height" => 8070
                "path" => "/media/geometrija_10/atanasjan-u23/2-00/716-1.webp?ts=1739441614"
              ]
            ]
          ]
          #changes: []
          #casts: []
          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
          #appends: []
          #dispatchesEvents: []
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          #touches: []
          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        2 => App\Models\Element {#1094
          #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" => 942402
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1084
              #items: array:1 [
                0 => App\Models\Edition {#1093
                  #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" => 2318
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 3"
                    "field_order" => "4"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1088 …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" => "3-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1089 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1085 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1087 …2}
                    "field_content_source" => null
                  ]
                  #original: array:21 [
                    "id" => 2318
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 3"
                    "field_order" => "4"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1088 …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" => "3-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1089 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1085 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1087 …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" => "745131"
              "type" => "task"
            ]
            "img" => array:2 [
              0 => array:5 [
                "name" => "716-1.jpg"
                "alt" => null
                "width" => "1373"
                "height" => 662
                "path" => "/media/geometrija_10/atanasjan-u23/3-00/716-1.webp?ts=1739437171"
              ]
              1 => array:5 [
                "name" => "716-2.jpg"
                "alt" => null
                "width" => "1373"
                "height" => 800
                "path" => "/media/geometrija_10/atanasjan-u23/3-00/716-2.webp?ts=1739437171"
              ]
            ]
          ]
          #original: array:6 [
            "id" => 942402
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1084}
            "task" => array:2 [
              "refs" => "745131"
              "type" => "task"
            ]
            "img" => array:2 [
              0 => array:5 [
                "name" => "716-1.jpg"
                "alt" => null
                "width" => "1373"
                "height" => 662
                "path" => "/media/geometrija_10/atanasjan-u23/3-00/716-1.webp?ts=1739437171"
              ]
              1 => array:5 [
                "name" => "716-2.jpg"
                "alt" => null
                "width" => "1373"
                "height" => 800
                "path" => "/media/geometrija_10/atanasjan-u23/3-00/716-2.webp?ts=1739437171"
              ]
            ]
          ]
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          #classCastCache: []
          #attributeCastCache: []
          #dateFormat: null
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          +timestamps: true
          +usesUniqueIds: false
          #hidden: []
          #visible: []
          #fillable: []
          #guarded: array:1 [
            0 => "*"
          ]
        }
        3 => App\Models\Element {#1102
          #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" => 941986
            "created_at" => "2026-04-10 13:58:26"
            "updated_at" => null
            "edition" => Illuminate\Database\Eloquent\Collection {#1092
              #items: array:1 [
                0 => App\Models\Edition {#1099
                  #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" => 2319
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 4"
                    "field_order" => "5"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1098 …2}
                    "field_content_type" => "free"
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                    "field_page_content_mode" => ""
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                    "field_page_content_text_checked" => "0"
                    "field_solution_author" => "Неизвестный"
                    "field_moderator" => "pasha"
                    "field_edition_type" => "solution"
                    "field_root_dir" => "4-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1096 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1090 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1095 …2}
                    "field_content_source" => null
                  ]
                  #original: array:21 [
                    "id" => 2319
                    "created_at" => "2026-04-10 13:58:26"
                    "updated_at" => null
                    "title" => "Решение 4"
                    "field_order" => "5"
                    "field_publisher" => Illuminate\Database\Eloquent\Collection {#1098 …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" => "4-"
                    "field_responsible" => Illuminate\Database\Eloquent\Collection {#1096 …2}
                    "field_comment" => null
                    "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1090 …2}
                    "field_process_formula" => ""
                    "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1095 …2}
                     …1
                  ]
                  #changes: []
                  #casts: []
                  #classCastCache: []
                  #attributeCastCache: []
                  #dateFormat: null
                  #appends: []
                  #dispatchesEvents: []
                  #observables: []
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                  #touches: []
                  +timestamps: true
                  +usesUniqueIds: false
                  #hidden: []
                  #visible: []
                  #fillable: []
                  #guarded: array:1 [ …1]
                }
              ]
              #escapeWhenCastingToString: false
            }
            "task" => array:2 [
              "refs" => "745131"
              "type" => "task"
            ]
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            "text" => "<p><strong>Решение</strong></p><p>Для решения этой задачи наиболее удобен векторный метод. Поместим вершину A в начало координат (0, 0, 0). Тогда векторы $\vec{AB}$, $\vec{AC}$ и $\vec{AD}$ будут радиус-векторами вершин B, C и D соответственно.</p><p>Точка пересечения медиан треугольника (центроид) делит каждую медиану в отношении 2:1, считая от вершины. Пусть M — точка пересечения медиан треугольника DBC. Её радиус-вектор $\vec{AM}$ можно найти по формуле центра масс для вершин B, C и D:</p><p>$\vec{AM} = \frac{1}{3}(\vec{AB} + \vec{AC} + \vec{AD})$</p><p>Искомое расстояние от вершины A до точки M — это длина (модуль) вектора $\vec{AM}$.</p><p>$|\vec{AM}| = \left| \frac{1}{3}(\vec{AB} + \vec{AC} + \vec{AD}) \right| = \frac{1}{3} |\vec{AB} + \vec{AC} + \vec{AD}|$</p><p>Для нахождения модуля вектора найдем его квадрат. Квадрат модуля вектора равен скалярному квадрату этого вектора.</p><p>$|\vec{AM}|^2 = \left( \frac{1}{3} |\vec{AB} + \vec{AC} + \vec{AD}| \right)^2 = \frac{1}{9} (\vec{AB} + \vec{AC} + \vec{AD}) \cdot (\vec{AB} + \vec{AC} + \vec{AD})$</p><p>Раскроем скобки, используя свойство дистрибутивности скалярного произведения:</p><p>$|\vec{AM}|^2 = \frac{1}{9} (|\vec{AB}|^2 + |\vec{AC}|^2 + |\vec{AD}|^2 + 2\vec{AB}\cdot\vec{AC} + 2\vec{AB}\cdot\vec{AD} + 2\vec{AC}\cdot\vec{AD})$</p><p>Теперь вычислим значения для каждого слагаемого, используя данные из условия задачи:</p><p>1. Квадраты модулей векторов:</p><ul><li>$|\vec{AB}|^2 = AB^2 = 4^2 = 16$</li> <li>$|\vec{AC}|^2 = AC^2 = 3^2 = 9$</li> <li>$|\vec{AD}|^2 = DA^2 = 5^2 = 25$</li></ul><p>2. Скалярные произведения векторов (используя формулу $\vec{a} \cdot \vec{b} = |\vec{a}| \cdot |\vec{b}| \cdot \cos \alpha$):</p><ul><li>$\vec{AB} \cdot \vec{AC} = |\vec{AB}| \cdot |\vec{AC}| \cdot \cos(\angle BAC) = 4 \cdot 3 \cdot \cos(90^\circ) = 12 \cdot 0 = 0$</li> <li>$\vec{AB} \cdot \vec{AD} = |\vec{AB}| \cdot |\vec{AD}| \cdot \cos(\angle DAB) = 4 \cdot 5 \cdot \cos(60^\circ) = 20 \cdot \frac{1}{2} = 10$</li> <li>$\vec{AC} \cdot \vec{AD} = |\vec{AC}| \cdot |\vec{AD}| \cdot \cos(\angle DAC) = 3 \cdot 5 \cdot \cos(45^\circ) = 15 \cdot \frac{\sqrt{2}}{2}$</li></ul><p>Подставим все найденные значения в выражение для квадрата модуля вектора $\vec{AM}$:</p><p>$|\vec{AM}|^2 = \frac{1}{9} \left( 16 + 9 + 25 + 2 \cdot 0 + 2 \cdot 10 + 2 \cdot \frac{15\sqrt{2}}{2} \right)$</p><p>$|\vec{AM}|^2 = \frac{1}{9} (16 + 9 + 25 + 0 + 20 + 15\sqrt{2})$</p><p>$|\vec{AM}|^2 = \frac{1}{9} (50 + 20 + 15\sqrt{2})$</p><p>$|\vec{AM}|^2 = \frac{1}{9} (70 + 15\sqrt{2})$</p><p>Чтобы найти расстояние AM, извлечем квадратный корень из полученного выражения:</p><p>$|\vec{AM}| = \sqrt{\frac{70 + 15\sqrt{2}}{9}} = \frac{\sqrt{70 + 15\sqrt{2}}}{3}$</p><p>Ответ: $\frac{\sqrt{70 + 15\sqrt{2}}}{3}$ см.</p>"
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            "text" => "<p><strong>Решение</strong></p><p>Для решения этой задачи наиболее удобен векторный метод. Поместим вершину A в начало координат (0, 0, 0). Тогда векторы $\vec{AB}$, $\vec{AC}$ и $\vec{AD}$ будут радиус-векторами вершин B, C и D соответственно.</p><p>Точка пересечения медиан треугольника (центроид) делит каждую медиану в отношении 2:1, считая от вершины. Пусть M — точка пересечения медиан треугольника DBC. Её радиус-вектор $\vec{AM}$ можно найти по формуле центра масс для вершин B, C и D:</p><p>$\vec{AM} = \frac{1}{3}(\vec{AB} + \vec{AC} + \vec{AD})$</p><p>Искомое расстояние от вершины A до точки M — это длина (модуль) вектора $\vec{AM}$.</p><p>$|\vec{AM}| = \left| \frac{1}{3}(\vec{AB} + \vec{AC} + \vec{AD}) \right| = \frac{1}{3} |\vec{AB} + \vec{AC} + \vec{AD}|$</p><p>Для нахождения модуля вектора найдем его квадрат. Квадрат модуля вектора равен скалярному квадрату этого вектора.</p><p>$|\vec{AM}|^2 = \left( \frac{1}{3} |\vec{AB} + \vec{AC} + \vec{AD}| \right)^2 = \frac{1}{9} (\vec{AB} + \vec{AC} + \vec{AD}) \cdot (\vec{AB} + \vec{AC} + \vec{AD})$</p><p>Раскроем скобки, используя свойство дистрибутивности скалярного произведения:</p><p>$|\vec{AM}|^2 = \frac{1}{9} (|\vec{AB}|^2 + |\vec{AC}|^2 + |\vec{AD}|^2 + 2\vec{AB}\cdot\vec{AC} + 2\vec{AB}\cdot\vec{AD} + 2\vec{AC}\cdot\vec{AD})$</p><p>Теперь вычислим значения для каждого слагаемого, используя данные из условия задачи:</p><p>1. Квадраты модулей векторов:</p><ul><li>$|\vec{AB}|^2 = AB^2 = 4^2 = 16$</li> <li>$|\vec{AC}|^2 = AC^2 = 3^2 = 9$</li> <li>$|\vec{AD}|^2 = DA^2 = 5^2 = 25$</li></ul><p>2. Скалярные произведения векторов (используя формулу $\vec{a} \cdot \vec{b} = |\vec{a}| \cdot |\vec{b}| \cdot \cos \alpha$):</p><ul><li>$\vec{AB} \cdot \vec{AC} = |\vec{AB}| \cdot |\vec{AC}| \cdot \cos(\angle BAC) = 4 \cdot 3 \cdot \cos(90^\circ) = 12 \cdot 0 = 0$</li> <li>$\vec{AB} \cdot \vec{AD} = |\vec{AB}| \cdot |\vec{AD}| \cdot \cos(\angle DAB) = 4 \cdot 5 \cdot \cos(60^\circ) = 20 \cdot \frac{1}{2} = 10$</li> <li>$\vec{AC} \cdot \vec{AD} = |\vec{AC}| \cdot |\vec{AD}| \cdot \cos(\angle DAC) = 3 \cdot 5 \cdot \cos(45^\circ) = 15 \cdot \frac{\sqrt{2}}{2}$</li></ul><p>Подставим все найденные значения в выражение для квадрата модуля вектора $\vec{AM}$:</p><p>$|\vec{AM}|^2 = \frac{1}{9} \left( 16 + 9 + 25 + 2 \cdot 0 + 2 \cdot 10 + 2 \cdot \frac{15\sqrt{2}}{2} \right)$</p><p>$|\vec{AM}|^2 = \frac{1}{9} (16 + 9 + 25 + 0 + 20 + 15\sqrt{2})$</p><p>$|\vec{AM}|^2 = \frac{1}{9} (50 + 20 + 15\sqrt{2})$</p><p>$|\vec{AM}|^2 = \frac{1}{9} (70 + 15\sqrt{2})$</p><p>Чтобы найти расстояние AM, извлечем квадратный корень из полученного выражения:</p><p>$|\vec{AM}| = \sqrt{\frac{70 + 15\sqrt{2}}{9}} = \frac{\sqrt{70 + 15\sqrt{2}}}{3}$</p><p>Ответ: $\frac{\sqrt{70 + 15\sqrt{2}}}{3}$ см.</p>"
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                5 => App\Models\Task {#1425
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                6 => App\Models\Task {#1444
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                7 => App\Models\Task {#1463
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                8 => App\Models\Task {#1482
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№716 (с. 179)
Условие. №716 (с. 179)
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 179, номер 716, Условие

716. В тетраэдре DABC DA = 5 см, AB = 4 см, АС = 3 см, ∠BAC = 90°, ∠DAB = 60°, ∠DAC = 45°. Найдите расстояние от вершины А до точки пересечения медиан треугольника DBC.

Решение 2. №716 (с. 179)
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 179, номер 716, Решение 2
Решение 3. №716 (с. 179)
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 179, номер 716, Решение 3
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 179, номер 716, Решение 3 (продолжение 2)
Решение 4. №716 (с. 179)
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 179, номер 716, Решение 4
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 179, номер 716, Решение 4 (продолжение 2)
Решение 6. №716 (с. 179)

Решение

Для решения этой задачи наиболее удобен векторный метод. Поместим вершину A в начало координат (0, 0, 0). Тогда векторы $\vec{AB}$, $\vec{AC}$ и $\vec{AD}$ будут радиус-векторами вершин B, C и D соответственно.

Точка пересечения медиан треугольника (центроид) делит каждую медиану в отношении 2:1, считая от вершины. Пусть M — точка пересечения медиан треугольника DBC. Её радиус-вектор $\vec{AM}$ можно найти по формуле центра масс для вершин B, C и D:

$\vec{AM} = \frac{1}{3}(\vec{AB} + \vec{AC} + \vec{AD})$

Искомое расстояние от вершины A до точки M — это длина (модуль) вектора $\vec{AM}$.

$|\vec{AM}| = \left| \frac{1}{3}(\vec{AB} + \vec{AC} + \vec{AD}) \right| = \frac{1}{3} |\vec{AB} + \vec{AC} + \vec{AD}|$

Для нахождения модуля вектора найдем его квадрат. Квадрат модуля вектора равен скалярному квадрату этого вектора.

$|\vec{AM}|^2 = \left( \frac{1}{3} |\vec{AB} + \vec{AC} + \vec{AD}| \right)^2 = \frac{1}{9} (\vec{AB} + \vec{AC} + \vec{AD}) \cdot (\vec{AB} + \vec{AC} + \vec{AD})$

Раскроем скобки, используя свойство дистрибутивности скалярного произведения:

$|\vec{AM}|^2 = \frac{1}{9} (|\vec{AB}|^2 + |\vec{AC}|^2 + |\vec{AD}|^2 + 2\vec{AB}\cdot\vec{AC} + 2\vec{AB}\cdot\vec{AD} + 2\vec{AC}\cdot\vec{AD})$

Теперь вычислим значения для каждого слагаемого, используя данные из условия задачи:

1. Квадраты модулей векторов:

  • $|\vec{AB}|^2 = AB^2 = 4^2 = 16$
  • $|\vec{AC}|^2 = AC^2 = 3^2 = 9$
  • $|\vec{AD}|^2 = DA^2 = 5^2 = 25$

2. Скалярные произведения векторов (используя формулу $\vec{a} \cdot \vec{b} = |\vec{a}| \cdot |\vec{b}| \cdot \cos \alpha$):

  • $\vec{AB} \cdot \vec{AC} = |\vec{AB}| \cdot |\vec{AC}| \cdot \cos(\angle BAC) = 4 \cdot 3 \cdot \cos(90^\circ) = 12 \cdot 0 = 0$
  • $\vec{AB} \cdot \vec{AD} = |\vec{AB}| \cdot |\vec{AD}| \cdot \cos(\angle DAB) = 4 \cdot 5 \cdot \cos(60^\circ) = 20 \cdot \frac{1}{2} = 10$
  • $\vec{AC} \cdot \vec{AD} = |\vec{AC}| \cdot |\vec{AD}| \cdot \cos(\angle DAC) = 3 \cdot 5 \cdot \cos(45^\circ) = 15 \cdot \frac{\sqrt{2}}{2}$

Подставим все найденные значения в выражение для квадрата модуля вектора $\vec{AM}$:

$|\vec{AM}|^2 = \frac{1}{9} \left( 16 + 9 + 25 + 2 \cdot 0 + 2 \cdot 10 + 2 \cdot \frac{15\sqrt{2}}{2} \right)$

$|\vec{AM}|^2 = \frac{1}{9} (16 + 9 + 25 + 0 + 20 + 15\sqrt{2})$

$|\vec{AM}|^2 = \frac{1}{9} (50 + 20 + 15\sqrt{2})$

$|\vec{AM}|^2 = \frac{1}{9} (70 + 15\sqrt{2})$

Чтобы найти расстояние AM, извлечем квадратный корень из полученного выражения:

$|\vec{AM}| = \sqrt{\frac{70 + 15\sqrt{2}}{9}} = \frac{\sqrt{70 + 15\sqrt{2}}}{3}$

Ответ: $\frac{\sqrt{70 + 15\sqrt{2}}}{3}$ см.

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