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Номер 814, страница 193 - гдз по геометрии 10-11 класс учебник Атанасян, Бутузов
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
Популярные ГДЗ в 10 классе
Глава 7. Метод координат в пространстве. Движения. Параграф 3. Движения, дополнительные задачи - номер 814, страница 193.
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" => 745229 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "193" "field_page_end" => null "field_url" => "/10-klass/geometrija/atanasjan-uchebnik/00-814" "field_display_title" => "814" "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 {#1198 #items: array:2 [ 0 => App\Models\Branch {#1077 #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 {#1080 #items: array:1 [ 0 => App\Models\Term {#1078 #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 {#1081 #items: array:1 [ 0 => App\Models\Book {#1082 #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 {#1083 …2} "field_class" => Illuminate\Database\Eloquent\Collection {#1085 …2} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1088 …2} "field_author" => Illuminate\Database\Eloquent\Collection {#1090 …2} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1096 …2} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1097 …2} "field_country" => Illuminate\Database\Eloquent\Collection {#1099 …2} "field_city" => Illuminate\Database\Eloquent\Collection {#1101 …2} "field_series" => Illuminate\Database\Eloquent\Collection {#1103 …2} "field_umk" => Illuminate\Database\Eloquent\Collection {#1104 …2} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1105 …2} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1107 …2} "field_publication_number" => "11" "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1109 …2} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1111 …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 {#1112 …2} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1113 …2} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1114 …2} "field_url" => "/10-klass/geometrija/atanasjan-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1115 …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 {#1083 …2} "field_class" => Illuminate\Database\Eloquent\Collection {#1085 …2} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1088 …2} "field_author" => Illuminate\Database\Eloquent\Collection {#1090 …2} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1096 …2} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1097 …2} "field_country" => Illuminate\Database\Eloquent\Collection {#1099 …2} "field_city" => Illuminate\Database\Eloquent\Collection {#1101 …2} "field_series" => Illuminate\Database\Eloquent\Collection {#1103 …2} "field_umk" => Illuminate\Database\Eloquent\Collection {#1104 …2} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1105 …2} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1107 …2} "field_publication_number" => "11" "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1109 …2} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1111 …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 {#1112 …2} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1113 …2} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1114 …2} "field_url" => "/10-klass/geometrija/atanasjan-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1115 …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 {#1117 #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 {#1080} "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 {#1081} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1117} ] #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 {#1118 #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 {#1119 #items: array:1 [ 0 => App\Models\Term {#1120 #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 {#1121 #items: array:1 [ 0 => App\Models\Book {#1122 #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 {#1123 …2} "field_class" => Illuminate\Database\Eloquent\Collection {#1125 …2} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1128 …2} "field_author" => Illuminate\Database\Eloquent\Collection {#1130 …2} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1136 …2} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1137 …2} "field_country" => Illuminate\Database\Eloquent\Collection {#1139 …2} "field_city" => Illuminate\Database\Eloquent\Collection {#1141 …2} "field_series" => Illuminate\Database\Eloquent\Collection {#1143 …2} "field_umk" => Illuminate\Database\Eloquent\Collection {#1144 …2} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1145 …2} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1147 …2} "field_publication_number" => "11" "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1149 …2} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1151 …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 {#1152 …2} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1153 …2} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1154 …2} "field_url" => "/10-klass/geometrija/atanasjan-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1155 …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 {#1123 …2} "field_class" => Illuminate\Database\Eloquent\Collection {#1125 …2} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1128 …2} "field_author" => Illuminate\Database\Eloquent\Collection {#1130 …2} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1136 …2} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1137 …2} "field_country" => Illuminate\Database\Eloquent\Collection {#1139 …2} "field_city" => Illuminate\Database\Eloquent\Collection {#1141 …2} "field_series" => Illuminate\Database\Eloquent\Collection {#1143 …2} "field_umk" => Illuminate\Database\Eloquent\Collection {#1144 …2} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1145 …2} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1147 …2} "field_publication_number" => "11" "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1149 …2} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1151 …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 {#1152 …2} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1153 …2} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1154 …2} "field_url" => "/10-klass/geometrija/atanasjan-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1155 …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 {#1157 #items: array:1 [ 0 => App\Models\Branch {#1158 #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 {#1159 …2} "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 {#1161 …2} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1197 …2} ] #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 {#1159 …2} "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 {#1161 …2} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1197 …2} ] #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" => 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 {#1119} "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 {#1121} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1157} ] #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 {#1201 #items: array:3 [ 0 => App\Models\Element {#1210 #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" => 940026 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1219 #items: array:1 [ 0 => App\Models\Edition {#1211 #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 {#1213 …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 {#1214 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1215 …2} "field_process_formula" => "wiris" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1216 …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 {#1213 …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 {#1214 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1215 …2} "field_process_formula" => "wiris" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1216 …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" => "745229" "type" => "task" ] "text" => "<p> <b>814.</b> Все высоты тетраэдра пересекаются в точке Н. Докажите, что точка Н, центр О описанной сферы и точка G пересечения отрезков, соединяющих вершины с точками пересечения медиан противоположных граней тетраэдра, лежат на одной прямой (прямая Эйлера), причём точки О и Н симметричны относительно точки G. </p>" "img" => array:1 [ 0 => array:5 [ "name" => "814-1.jpg" "alt" => null "width" => "1559" "height" => 297 "path" => "/media/geometrija_10/atanasjan-u23/0-00/814-1.webp?ts=1739436917" ] ] ] #original: array:7 [ "id" => 940026 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1219} "task" => array:2 [ "refs" => "745229" "type" => "task" ] "text" => "<p> <b>814.</b> Все высоты тетраэдра пересекаются в точке Н. Докажите, что точка Н, центр О описанной сферы и точка G пересечения отрезков, соединяющих вершины с точками пересечения медиан противоположных граней тетраэдра, лежат на одной прямой (прямая Эйлера), причём точки О и Н симметричны относительно точки G. </p>" "img" => array:1 [ 0 => array:5 [ "name" => "814-1.jpg" "alt" => null "width" => "1559" "height" => 297 "path" => "/media/geometrija_10/atanasjan-u23/0-00/814-1.webp?ts=1739436917" ] ] ] #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 {#1217 #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" => 942775 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1227 #items: array:1 [ 0 => App\Models\Edition {#1218 #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 {#1221 …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 {#1222 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1223 …2} "field_process_formula" => "" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1224 …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 {#1221 …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 {#1222 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1223 …2} "field_process_formula" => "" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1224 …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" => "745229" "type" => "task" ] "img" => array:1 [ 0 => array:5 [ "name" => "814-1.png" "alt" => null "width" => "694" "height" => 5193 "path" => "/media/geometrija_10/atanasjan-u23/2-00/814-1.webp?ts=1739441717" ] ] ] #original: array:6 [ "id" => 942775 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1227} "task" => array:2 [ "refs" => "745229" "type" => "task" ] "img" => array:1 [ 0 => array:5 [ "name" => "814-1.png" "alt" => null "width" => "694" "height" => 5193 "path" => "/media/geometrija_10/atanasjan-u23/2-00/814-1.webp?ts=1739441717" ] ] ] #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 {#1225 #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" => 1352542 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1235 #items: array:1 [ 0 => App\Models\Edition {#1226 #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 {#1229 …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 {#1230 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1231 …2} "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1232 …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 {#1229 …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 {#1230 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1231 …2} "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1232 …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" => "745229" "type" => "task" ] "text" => "<p>Для доказательства воспользуемся векторным методом. Пусть $A$, $B$, $C$, $D$ — вершины тетраэдра. Введем систему координат с началом в точке $O$ — центре описанной сферы. Тогда радиус-векторы вершин тетраэдра, которые мы обозначим как $\vec{a}$, $\vec{b}$, $\vec{c}$, $\vec{d}$, будут удовлетворять условию равенства их модулей радиусу $R$ описанной сферы:</p><p>$|\vec{a}| = |\vec{b}| = |\vec{c}| = |\vec{d}| = R$</p><p>В квадрате это равенство выглядит так: $\vec{a}^2 = \vec{b}^2 = \vec{c}^2 = \vec{d}^2 = R^2$.</p><p>Точка $G$, являющаяся точкой пересечения отрезков, соединяющих вершины с центроидами (точками пересечения медиан) противоположных граней, есть не что иное, как центроид (или центр масс) всего тетраэдра. Её радиус-вектор $\vec{g}$ выражается как среднее арифметическое радиус-векторов вершин:</p><p>$\vec{g} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$</p><p>По условию, все высоты тетраэдра пересекаются в одной точке $H$. Такой тетраэдр называется ортоцентрическим. Важнейшим свойством ортоцентрического тетраэдра является то, что суммы квадратов длин его противоположных ребер равны. В векторном виде, с началом координат в центре описанной сферы $O$, это свойство эквивалентно следующему соотношению для скалярных произведений векторов вершин:</p><p>$\vec{a} \cdot \vec{b} + \vec{c} \cdot \vec{d} = \vec{a} \cdot \vec{c} + \vec{b} \cdot \vec{d} = \vec{a} \cdot \vec{d} + \vec{b} \cdot \vec{c}$</p><p>Теперь найдем радиус-вектор $\vec{h}$ ортоцентра $H$. Рассмотрим точку $P$, радиус-вектор которой $\vec{p}$ определяется формулой:</p><p>$\vec{p} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$</p><p>Докажем, что эта точка $P$ лежит на каждой из высот тетраэдра. Для этого достаточно показать, что вектор, соединяющий вершину (например, $A$) с точкой $P$, перпендикулярен противоположной грани ($BCD$). Вектор $\vec{AP}$ равен $\vec{p} - \vec{a}$:</p><p>$\vec{AP} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2} - \vec{a} = \frac{-\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$</p><p>Проверим перпендикулярность этого вектора векторам, лежащим в плоскости грани $BCD$, например, $\vec{BC} = \vec{c} - \vec{b}$ и $\vec{BD} = \vec{d} - \vec{b}$.</p><p>$\vec{AP} \cdot \vec{BC} = \frac{1}{2}(-\vec{a} + \vec{b} + \vec{c} + \vec{d}) \cdot (\vec{c} - \vec{b})$<br>$= \frac{1}{2}(-\vec{a}\cdot\vec{c} + \vec{a}\cdot\vec{b} + \vec{b}\cdot\vec{c} - \vec{b}^2 + \vec{c}^2 - \vec{c}\cdot\vec{b} + \vec{d}\cdot\vec{c} - \vec{d}\cdot\vec{b})$<br>$= \frac{1}{2}(-\vec{a}\cdot\vec{c} + \vec{a}\cdot\vec{b} - R^2 + R^2 + \vec{c}\cdot\vec{d} - \vec{b}\cdot\vec{d})$<br>$= \frac{1}{2}[(\vec{a}\cdot\vec{b} + \vec{c}\cdot\vec{d}) - (\vec{a}\cdot\vec{c} + \vec{b}\cdot\vec{d})]$</p><p>Поскольку тетраэдр ортоцентрический, выражение в квадратных скобках равно нулю. Следовательно, $\vec{AP} \perp \vec{BC}$. Аналогично доказывается, что $\vec{AP} \perp \vec{BD}$. Таким образом, вектор $\vec{AP}$ перпендикулярен плоскости $BCD$, а значит, точка $P$ лежит на высоте, опущенной из вершины $A$.</p><p>В силу симметрии формулы для $\vec{p}$, аналогичные рассуждения показывают, что точка $P$ лежит на всех четырех высотах тетраэдра. Так как по условию все высоты пересекаются в точке $H$, то точка $P$ и есть ортоцентр $H$. Итак, радиус-вектор ортоцентра:</p><p>$\vec{h} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$</p><p>Теперь мы можем доказать утверждения задачи.</p><p><strong>Доказательство того, что точки H, O и G лежат на одной прямой (прямая Эйлера)</strong></p><p>Имеем радиус-векторы точек $O$, $G$ и $H$:</p><p>$\vec{o} = \vec{0}$<br>$\vec{g} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$<br>$\vec{h} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$</p><p>Рассмотрим векторы $\vec{OG}$ и $\vec{OH}$:</p><p>$\vec{OG} = \vec{g} - \vec{o} = \vec{g} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$<br>$\vec{OH} = \vec{h} - \vec{o} = \vec{h} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$</p><p>Из этих выражений видно, что $\vec{OH} = 2 \cdot \vec{OG}$.</p><p>Поскольку вектор $\vec{OH}$ является произведением вектора $\vec{OG}$ на скаляр (число 2), эти векторы коллинеарны. Так как они исходят из одной точки $O$, точки $O$, $G$ и $H$ лежат на одной прямой.</p><p><strong>Доказательство того, что точки O и H симметричны относительно точки G</strong></p><p>Точки $O$ и $H$ симметричны относительно точки $G$, если $G$ является серединой отрезка $OH$. В векторной форме это означает, что радиус-вектор точки $G$ должен быть равен полусумме радиус-векторов точек $O$ и $H$. Проверим это условие:</p><p>$\frac{\vec{o} + \vec{h}}{2} = \frac{\vec{0} + \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}}{2} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$</p><p>Полученное выражение в точности совпадает с радиус-вектором точки $G$: $\vec{g} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$.</p><p>Таким образом, $\vec{g} = \frac{\vec{o} + \vec{h}}{2}$, что и доказывает, что точка $G$ является серединой отрезка $OH$, а значит, точки $O$ и $H$ симметричны относительно $G$.</p><p>Оба утверждения доказаны.</p><p><strong>Ответ:</strong> Утверждение доказано. В ортоцентрическом тетраэдре центр описанной сферы $O$, центроид $G$ и ортоцентр $H$ лежат на одной прямой (прямой Эйлера), причем точка $G$ является серединой отрезка $OH$, что означает симметричность точек $O$ и $H$ относительно точки $G$.</p>" ] #original: array:6 [ "id" => 1352542 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1235} "task" => array:2 [ "refs" => "745229" "type" => "task" ] "text" => "<p>Для доказательства воспользуемся векторным методом. Пусть $A$, $B$, $C$, $D$ — вершины тетраэдра. Введем систему координат с началом в точке $O$ — центре описанной сферы. Тогда радиус-векторы вершин тетраэдра, которые мы обозначим как $\vec{a}$, $\vec{b}$, $\vec{c}$, $\vec{d}$, будут удовлетворять условию равенства их модулей радиусу $R$ описанной сферы:</p><p>$|\vec{a}| = |\vec{b}| = |\vec{c}| = |\vec{d}| = R$</p><p>В квадрате это равенство выглядит так: $\vec{a}^2 = \vec{b}^2 = \vec{c}^2 = \vec{d}^2 = R^2$.</p><p>Точка $G$, являющаяся точкой пересечения отрезков, соединяющих вершины с центроидами (точками пересечения медиан) противоположных граней, есть не что иное, как центроид (или центр масс) всего тетраэдра. Её радиус-вектор $\vec{g}$ выражается как среднее арифметическое радиус-векторов вершин:</p><p>$\vec{g} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$</p><p>По условию, все высоты тетраэдра пересекаются в одной точке $H$. Такой тетраэдр называется ортоцентрическим. Важнейшим свойством ортоцентрического тетраэдра является то, что суммы квадратов длин его противоположных ребер равны. В векторном виде, с началом координат в центре описанной сферы $O$, это свойство эквивалентно следующему соотношению для скалярных произведений векторов вершин:</p><p>$\vec{a} \cdot \vec{b} + \vec{c} \cdot \vec{d} = \vec{a} \cdot \vec{c} + \vec{b} \cdot \vec{d} = \vec{a} \cdot \vec{d} + \vec{b} \cdot \vec{c}$</p><p>Теперь найдем радиус-вектор $\vec{h}$ ортоцентра $H$. Рассмотрим точку $P$, радиус-вектор которой $\vec{p}$ определяется формулой:</p><p>$\vec{p} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$</p><p>Докажем, что эта точка $P$ лежит на каждой из высот тетраэдра. Для этого достаточно показать, что вектор, соединяющий вершину (например, $A$) с точкой $P$, перпендикулярен противоположной грани ($BCD$). Вектор $\vec{AP}$ равен $\vec{p} - \vec{a}$:</p><p>$\vec{AP} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2} - \vec{a} = \frac{-\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$</p><p>Проверим перпендикулярность этого вектора векторам, лежащим в плоскости грани $BCD$, например, $\vec{BC} = \vec{c} - \vec{b}$ и $\vec{BD} = \vec{d} - \vec{b}$.</p><p>$\vec{AP} \cdot \vec{BC} = \frac{1}{2}(-\vec{a} + \vec{b} + \vec{c} + \vec{d}) \cdot (\vec{c} - \vec{b})$<br>$= \frac{1}{2}(-\vec{a}\cdot\vec{c} + \vec{a}\cdot\vec{b} + \vec{b}\cdot\vec{c} - \vec{b}^2 + \vec{c}^2 - \vec{c}\cdot\vec{b} + \vec{d}\cdot\vec{c} - \vec{d}\cdot\vec{b})$<br>$= \frac{1}{2}(-\vec{a}\cdot\vec{c} + \vec{a}\cdot\vec{b} - R^2 + R^2 + \vec{c}\cdot\vec{d} - \vec{b}\cdot\vec{d})$<br>$= \frac{1}{2}[(\vec{a}\cdot\vec{b} + \vec{c}\cdot\vec{d}) - (\vec{a}\cdot\vec{c} + \vec{b}\cdot\vec{d})]$</p><p>Поскольку тетраэдр ортоцентрический, выражение в квадратных скобках равно нулю. Следовательно, $\vec{AP} \perp \vec{BC}$. Аналогично доказывается, что $\vec{AP} \perp \vec{BD}$. Таким образом, вектор $\vec{AP}$ перпендикулярен плоскости $BCD$, а значит, точка $P$ лежит на высоте, опущенной из вершины $A$.</p><p>В силу симметрии формулы для $\vec{p}$, аналогичные рассуждения показывают, что точка $P$ лежит на всех четырех высотах тетраэдра. Так как по условию все высоты пересекаются в точке $H$, то точка $P$ и есть ортоцентр $H$. Итак, радиус-вектор ортоцентра:</p><p>$\vec{h} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$</p><p>Теперь мы можем доказать утверждения задачи.</p><p><strong>Доказательство того, что точки H, O и G лежат на одной прямой (прямая Эйлера)</strong></p><p>Имеем радиус-векторы точек $O$, $G$ и $H$:</p><p>$\vec{o} = \vec{0}$<br>$\vec{g} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$<br>$\vec{h} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$</p><p>Рассмотрим векторы $\vec{OG}$ и $\vec{OH}$:</p><p>$\vec{OG} = \vec{g} - \vec{o} = \vec{g} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$<br>$\vec{OH} = \vec{h} - \vec{o} = \vec{h} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$</p><p>Из этих выражений видно, что $\vec{OH} = 2 \cdot \vec{OG}$.</p><p>Поскольку вектор $\vec{OH}$ является произведением вектора $\vec{OG}$ на скаляр (число 2), эти векторы коллинеарны. Так как они исходят из одной точки $O$, точки $O$, $G$ и $H$ лежат на одной прямой.</p><p><strong>Доказательство того, что точки O и H симметричны относительно точки G</strong></p><p>Точки $O$ и $H$ симметричны относительно точки $G$, если $G$ является серединой отрезка $OH$. В векторной форме это означает, что радиус-вектор точки $G$ должен быть равен полусумме радиус-векторов точек $O$ и $H$. Проверим это условие:</p><p>$\frac{\vec{o} + \vec{h}}{2} = \frac{\vec{0} + \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}}{2} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$</p><p>Полученное выражение в точности совпадает с радиус-вектором точки $G$: $\vec{g} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$.</p><p>Таким образом, $\vec{g} = \frac{\vec{o} + \vec{h}}{2}$, что и доказывает, что точка $G$ является серединой отрезка $OH$, а значит, точки $O$ и $H$ симметричны относительно $G$.</p><p>Оба утверждения доказаны.</p><p><strong>Ответ:</strong> Утверждение доказано. В ортоцентрическом тетраэдре центр описанной сферы $O$, центроид $G$ и ортоцентр $H$ лежат на одной прямой (прямой Эйлера), причем точка $G$ является серединой отрезка $OH$, что означает симметричность точек $O$ и $H$ относительно точки $G$.</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" => "745230" "type" => "task" ] "previous" => array:2 [ "refs" => "745228" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1262 #items: array:1 [ 0 => App\Models\Book {#1207 #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 {#1200 #items: array:1 [ 0 => App\Models\Term {#1199 #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 {#1206 #items: array:2 [ 0 => App\Models\Term {#1208 #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 {#1204 #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] …1 ] #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_publisher" => Illuminate\Database\Eloquent\Collection {#1202 #items: array:1 [ 0 => App\Models\Term {#1205 #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_author" => Illuminate\Database\Eloquent\Collection {#1203 #items: array:5 [ 0 => App\Models\Term {#1233 #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 {#1234 #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 {#1236 #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 {#1237 #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 {#1238 #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 {#1239 #items: [] #escapeWhenCastingToString: false } "field_book_type" => Illuminate\Database\Eloquent\Collection {#1240 #items: array:1 [ 0 => App\Models\Term {#1241 #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 {#1242 #items: array:1 [ 0 => App\Models\Term {#1243 #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 {#1244 #items: array:1 [ 0 => App\Models\Term {#1245 #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 {#1246 #items: [] #escapeWhenCastingToString: false } "field_umk" => Illuminate\Database\Eloquent\Collection {#1247 #items: [] #escapeWhenCastingToString: false } "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1248 #items: array:1 [ 0 => App\Models\Term {#1249 #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 {#1250 #items: array:1 [ 0 => App\Models\Term {#1251 #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 {#1252 #items: array:1 [ 0 => App\Models\Term {#1253 #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 {#1254 #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 {#1255 #items: [] #escapeWhenCastingToString: false } "field_new_book" => Illuminate\Database\Eloquent\Collection {#1256 #items: [] #escapeWhenCastingToString: false } "field_old_book" => Illuminate\Database\Eloquent\Collection {#1257 #items: [] #escapeWhenCastingToString: false } "field_url" => "/10-klass/geometrija/atanasjan-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1258 #items: array:1 [ 0 => App\Models\Term {#1259 #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 {#1200} "field_class" => Illuminate\Database\Eloquent\Collection {#1206} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1202} "field_author" => Illuminate\Database\Eloquent\Collection {#1203} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1239} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1240} "field_country" => Illuminate\Database\Eloquent\Collection {#1242} "field_city" => Illuminate\Database\Eloquent\Collection {#1244} "field_series" => Illuminate\Database\Eloquent\Collection {#1246} "field_umk" => Illuminate\Database\Eloquent\Collection {#1247} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1248} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1250} "field_publication_number" => "11" "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1252} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1254} "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 {#1255} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1256} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1257} "field_url" => "/10-klass/geometrija/atanasjan-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1258} "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 } "page" => Illuminate\Database\Eloquent\Collection {#1267 #items: array:1 [ 0 => App\Models\BookPage {#1266 #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" => 933975 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "193" "field_url" => "/10-klass/geometrija/atanasjan-uchebnik/page-193" "field_display_title" => "193" "field_folder" => "1" "field_image_name" => "193" "field_branch_parent" => Illuminate\Database\Eloquent\Collection {#1268 #items: [] #escapeWhenCastingToString: false } "field_weight" => "0" "field_book_parent" => Illuminate\Database\Eloquent\Collection {#1269 #items: array:1 [ 0 => App\Models\Book {#1207} ] #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 {#1270 #items: [] #escapeWhenCastingToString: false } "content" => Illuminate\Database\Eloquent\Collection {#1280 #items: array:1 [ 0 => App\Models\Element {#1279 #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" => "933976" "type" => "book_page" ] "previous" => array:2 [ "refs" => "933974" "type" => "book_page" ] "tasks" => Illuminate\Database\Eloquent\Collection {#1504 #items: array:8 [ 0 => App\Models\Task {#1518 #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 {#1524 #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 {#1529 #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 {#1543 #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 {#1557 #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 {#1571 #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 {#1585 #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 {#1597 #connection: "mysql" #table: "tasks" #primaryKey: "id" #keyType: "int" +incrementing: true #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false 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№814 (с. 193)
Условие. №814 (с. 193)
скриншот условия
814. Все высоты тетраэдра пересекаются в точке Н. Докажите, что точка Н, центр О описанной сферы и точка G пересечения отрезков, соединяющих вершины с точками пересечения медиан противоположных граней тетраэдра, лежат на одной прямой (прямая Эйлера), причём точки О и Н симметричны относительно точки G.
Решение 2. №814 (с. 193)
Решение 6. №814 (с. 193)
Для доказательства воспользуемся векторным методом. Пусть $A$, $B$, $C$, $D$ — вершины тетраэдра. Введем систему координат с началом в точке $O$ — центре описанной сферы. Тогда радиус-векторы вершин тетраэдра, которые мы обозначим как $\vec{a}$, $\vec{b}$, $\vec{c}$, $\vec{d}$, будут удовлетворять условию равенства их модулей радиусу $R$ описанной сферы:
$|\vec{a}| = |\vec{b}| = |\vec{c}| = |\vec{d}| = R$
В квадрате это равенство выглядит так: $\vec{a}^2 = \vec{b}^2 = \vec{c}^2 = \vec{d}^2 = R^2$.
Точка $G$, являющаяся точкой пересечения отрезков, соединяющих вершины с центроидами (точками пересечения медиан) противоположных граней, есть не что иное, как центроид (или центр масс) всего тетраэдра. Её радиус-вектор $\vec{g}$ выражается как среднее арифметическое радиус-векторов вершин:
$\vec{g} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$
По условию, все высоты тетраэдра пересекаются в одной точке $H$. Такой тетраэдр называется ортоцентрическим. Важнейшим свойством ортоцентрического тетраэдра является то, что суммы квадратов длин его противоположных ребер равны. В векторном виде, с началом координат в центре описанной сферы $O$, это свойство эквивалентно следующему соотношению для скалярных произведений векторов вершин:
$\vec{a} \cdot \vec{b} + \vec{c} \cdot \vec{d} = \vec{a} \cdot \vec{c} + \vec{b} \cdot \vec{d} = \vec{a} \cdot \vec{d} + \vec{b} \cdot \vec{c}$
Теперь найдем радиус-вектор $\vec{h}$ ортоцентра $H$. Рассмотрим точку $P$, радиус-вектор которой $\vec{p}$ определяется формулой:
$\vec{p} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$
Докажем, что эта точка $P$ лежит на каждой из высот тетраэдра. Для этого достаточно показать, что вектор, соединяющий вершину (например, $A$) с точкой $P$, перпендикулярен противоположной грани ($BCD$). Вектор $\vec{AP}$ равен $\vec{p} - \vec{a}$:
$\vec{AP} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2} - \vec{a} = \frac{-\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$
Проверим перпендикулярность этого вектора векторам, лежащим в плоскости грани $BCD$, например, $\vec{BC} = \vec{c} - \vec{b}$ и $\vec{BD} = \vec{d} - \vec{b}$.
$\vec{AP} \cdot \vec{BC} = \frac{1}{2}(-\vec{a} + \vec{b} + \vec{c} + \vec{d}) \cdot (\vec{c} - \vec{b})$
$= \frac{1}{2}(-\vec{a}\cdot\vec{c} + \vec{a}\cdot\vec{b} + \vec{b}\cdot\vec{c} - \vec{b}^2 + \vec{c}^2 - \vec{c}\cdot\vec{b} + \vec{d}\cdot\vec{c} - \vec{d}\cdot\vec{b})$
$= \frac{1}{2}(-\vec{a}\cdot\vec{c} + \vec{a}\cdot\vec{b} - R^2 + R^2 + \vec{c}\cdot\vec{d} - \vec{b}\cdot\vec{d})$
$= \frac{1}{2}[(\vec{a}\cdot\vec{b} + \vec{c}\cdot\vec{d}) - (\vec{a}\cdot\vec{c} + \vec{b}\cdot\vec{d})]$
Поскольку тетраэдр ортоцентрический, выражение в квадратных скобках равно нулю. Следовательно, $\vec{AP} \perp \vec{BC}$. Аналогично доказывается, что $\vec{AP} \perp \vec{BD}$. Таким образом, вектор $\vec{AP}$ перпендикулярен плоскости $BCD$, а значит, точка $P$ лежит на высоте, опущенной из вершины $A$.
В силу симметрии формулы для $\vec{p}$, аналогичные рассуждения показывают, что точка $P$ лежит на всех четырех высотах тетраэдра. Так как по условию все высоты пересекаются в точке $H$, то точка $P$ и есть ортоцентр $H$. Итак, радиус-вектор ортоцентра:
$\vec{h} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$
Теперь мы можем доказать утверждения задачи.
Доказательство того, что точки H, O и G лежат на одной прямой (прямая Эйлера)
Имеем радиус-векторы точек $O$, $G$ и $H$:
$\vec{o} = \vec{0}$
$\vec{g} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$
$\vec{h} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$
Рассмотрим векторы $\vec{OG}$ и $\vec{OH}$:
$\vec{OG} = \vec{g} - \vec{o} = \vec{g} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$
$\vec{OH} = \vec{h} - \vec{o} = \vec{h} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}$
Из этих выражений видно, что $\vec{OH} = 2 \cdot \vec{OG}$.
Поскольку вектор $\vec{OH}$ является произведением вектора $\vec{OG}$ на скаляр (число 2), эти векторы коллинеарны. Так как они исходят из одной точки $O$, точки $O$, $G$ и $H$ лежат на одной прямой.
Доказательство того, что точки O и H симметричны относительно точки G
Точки $O$ и $H$ симметричны относительно точки $G$, если $G$ является серединой отрезка $OH$. В векторной форме это означает, что радиус-вектор точки $G$ должен быть равен полусумме радиус-векторов точек $O$ и $H$. Проверим это условие:
$\frac{\vec{o} + \vec{h}}{2} = \frac{\vec{0} + \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{2}}{2} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$
Полученное выражение в точности совпадает с радиус-вектором точки $G$: $\vec{g} = \frac{\vec{a} + \vec{b} + \vec{c} + \vec{d}}{4}$.
Таким образом, $\vec{g} = \frac{\vec{o} + \vec{h}}{2}$, что и доказывает, что точка $G$ является серединой отрезка $OH$, а значит, точки $O$ и $H$ симметричны относительно $G$.
Оба утверждения доказаны.
Ответ: Утверждение доказано. В ортоцентрическом тетраэдре центр описанной сферы $O$, центроид $G$ и ортоцентр $H$ лежат на одной прямой (прямой Эйлера), причем точка $G$ является серединой отрезка $OH$, что означает симметричность точек $O$ и $H$ относительно точки $G$.
Другие задания:
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