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Номер 740, страница 212 - гдз по алгебре 9 класс учебник Солтан, Солтан
Авторы: Солтан Г. Н., Солтан А. Е., Жумадилова А. Ж.
Тип: Учебник
Издательство: Кокшетау
Год издания: 2019 - 2026
ISBN: 978-601-317-424-2
Рекомендовано Министерством образования и науки Республики Казахстан
Популярные ГДЗ в 9 классе
IV. Тригонометрия. 28. Преобразование суммы и разности тригонометрических функций в произведение - номер 740, страница 212.
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" => 1108482 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "212" "field_page_end" => null "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik/1-740" "field_display_title" => "740" "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 {#1071 #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" => 1107662 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "IV. Тригонометрия" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1039 #items: [] #escapeWhenCastingToString: false } "field_page_start" => "147" "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 {#1038 #items: array:1 [ 0 => App\Models\Book {#1040 #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" => 4298 "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 {#1041 …2} "field_class" => Illuminate\Database\Eloquent\Collection {#1043 …2} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1045 …2} "field_author" => Illuminate\Database\Eloquent\Collection {#1047 …2} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1051 …2} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1052 …2} "field_country" => Illuminate\Database\Eloquent\Collection {#1054 …2} "field_city" => Illuminate\Database\Eloquent\Collection {#1056 …2} "field_series" => Illuminate\Database\Eloquent\Collection {#1058 …2} "field_umk" => Illuminate\Database\Eloquent\Collection {#1059 …2} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1060 …2} "field_standart_of_education" => 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"field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1064 …2} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1065 …2} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1066 …2} "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1067 …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" => 4298 "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 {#1041 …2} "field_class" => Illuminate\Database\Eloquent\Collection {#1043 …2} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1045 …2} "field_author" => Illuminate\Database\Eloquent\Collection {#1047 …2} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1051 …2} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1052 …2} "field_country" => Illuminate\Database\Eloquent\Collection {#1054 …2} "field_city" => Illuminate\Database\Eloquent\Collection {#1056 …2} "field_series" => Illuminate\Database\Eloquent\Collection {#1058 …2} "field_umk" => Illuminate\Database\Eloquent\Collection {#1059 …2} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1060 …2} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1061 …2} "field_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1062 …2} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1063 …2} "field_under_the_edition_degree" => null "field_cover_description" => null "field_publication_year" => "2019" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебник для учащихся 9 класса общеобразовательных школ" "field_allowed" => "Рекомендовано Министерством образования и науки Республики Казахстан" "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "1291" "field_priority" => "4" "field_default_folder" => "/algebra_09/soltan-u19/" "field_isbn" => "978-601-317-424-2" "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 {#1064 …2} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1065 …2} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1066 …2} "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1067 …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 {#1068 #items: [] #escapeWhenCastingToString: false } ] #original: array:24 [ "id" => 1107662 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "IV. 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"field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1097 …2} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1098 …2} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1099 …2} "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1100 …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" => 4298 "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 {#1074 …2} "field_class" => Illuminate\Database\Eloquent\Collection {#1076 …2} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1078 …2} "field_author" => Illuminate\Database\Eloquent\Collection {#1080 …2} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1084 …2} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1085 …2} "field_country" => Illuminate\Database\Eloquent\Collection {#1087 …2} "field_city" => Illuminate\Database\Eloquent\Collection {#1089 …2} "field_series" => Illuminate\Database\Eloquent\Collection {#1091 …2} "field_umk" => Illuminate\Database\Eloquent\Collection {#1092 …2} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1093 …2} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1094 …2} "field_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1095 …2} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1096 …2} "field_under_the_edition_degree" => null "field_cover_description" => null "field_publication_year" => "2019" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебник для учащихся 9 класса общеобразовательных школ" "field_allowed" => "Рекомендовано Министерством образования и науки Республики Казахстан" "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "1291" "field_priority" => "4" "field_default_folder" => "/algebra_09/soltan-u19/" "field_isbn" => "978-601-317-424-2" "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 {#1097 …2} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1098 …2} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1099 …2} "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1100 …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 {#1101 #items: [] #escapeWhenCastingToString: false } ] #original: array:24 [ "id" => 1107662 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "IV. Тригонометрия" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1072} "field_page_start" => "147" "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 {#1070} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1101} ] #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 {#1102 #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" => 1107670 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "28. Преобразование суммы и разности тригонометрических функций в произведение" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1103 #items: [] #escapeWhenCastingToString: false } "field_page_start" => "210" "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 {#1104 #items: array:1 [ 0 => App\Models\Book {#1105 #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" => 4298 "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 {#1106 …2} "field_class" => Illuminate\Database\Eloquent\Collection {#1108 …2} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1110 …2} "field_author" => Illuminate\Database\Eloquent\Collection {#1112 …2} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1116 …2} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1117 …2} "field_country" => Illuminate\Database\Eloquent\Collection {#1119 …2} "field_city" => Illuminate\Database\Eloquent\Collection {#1121 …2} "field_series" => Illuminate\Database\Eloquent\Collection {#1123 …2} "field_umk" => Illuminate\Database\Eloquent\Collection {#1124 …2} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1125 …2} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1126 …2} "field_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1127 …2} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1128 …2} "field_under_the_edition_degree" => null "field_cover_description" => null "field_publication_year" => "2019" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебник для учащихся 9 класса общеобразовательных школ" "field_allowed" => "Рекомендовано Министерством образования и науки Республики Казахстан" "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "1291" "field_priority" => "4" "field_default_folder" => "/algebra_09/soltan-u19/" "field_isbn" => "978-601-317-424-2" "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 {#1129 …2} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1130 …2} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1131 …2} "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1132 …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" => 4298 "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 {#1106 …2} "field_class" => Illuminate\Database\Eloquent\Collection {#1108 …2} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1110 …2} "field_author" => Illuminate\Database\Eloquent\Collection {#1112 …2} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1116 …2} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1117 …2} "field_country" => Illuminate\Database\Eloquent\Collection {#1119 …2} "field_city" => Illuminate\Database\Eloquent\Collection {#1121 …2} "field_series" => Illuminate\Database\Eloquent\Collection {#1123 …2} "field_umk" => Illuminate\Database\Eloquent\Collection {#1124 …2} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1125 …2} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1126 …2} "field_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1127 …2} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1128 …2} "field_under_the_edition_degree" => null "field_cover_description" => null "field_publication_year" => "2019" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебник для учащихся 9 класса общеобразовательных школ" "field_allowed" => "Рекомендовано Министерством образования и науки Республики Казахстан" "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "1291" "field_priority" => "4" "field_default_folder" => "/algebra_09/soltan-u19/" "field_isbn" => "978-601-317-424-2" "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 {#1129 …2} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1130 …2} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1131 …2} "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1132 …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 {#1133 #items: array:1 [ 0 => App\Models\Branch {#1134 #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" => 1107662 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "IV. Тригонометрия" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1135 …2} "field_page_start" => "147" "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 {#1136 …2} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1137 …2} ] #original: array:24 [ "id" => 1107662 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "IV. Тригонометрия" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1135 …2} "field_page_start" => "147" "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 {#1136 …2} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1137 …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" => 1107670 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_display_title" => "28. Преобразование суммы и разности тригонометрических функций в произведение" "field_branch_order" => null "field_url" => null "field_branch_type" => Illuminate\Database\Eloquent\Collection {#1103} "field_page_start" => "210" "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 {#1104} "branch_parent" => Illuminate\Database\Eloquent\Collection {#1133} ] #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 {#1141 #items: array:3 [ 0 => App\Models\Element {#1150 #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" => 1277095 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1159 #items: array:1 [ 0 => App\Models\Edition {#1151 #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" => 4953 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Условие" "field_order" => "1" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1153 …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 {#1154 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1155 …2} "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1156 …2} "field_content_source" => null ] #original: array:21 [ "id" => 4953 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Условие" "field_order" => "1" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1153 …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 {#1154 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1155 …2} "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1156 …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" => "1108482" "type" => "task" ] "text" => "<p><strong>740.</strong> Преобразуйте в произведение выражение:</p><p><strong>а)</strong> $ \sin 20^\circ + \sin 40^\circ $;</p><p><strong>б)</strong> $ \sin 55^\circ - \sin(-65^\circ) $;</p><p><strong>в)</strong> $ \cos 12^\circ + \sin 42^\circ $;</p><p><strong>г)</strong> $ \cos(-50^\circ) - \sin 20^\circ $;</p><p><strong>д)</strong> $ \sin 255^\circ - \sin 165^\circ $;</p><p><strong>е)</strong> $ \cos 315^\circ + \cos 225^\circ $.</p>" "img" => array:1 [ 0 => array:5 [ "name" => "740-1.jpg" "alt" => null "width" => "1139" "height" => 323 "path" => "/media/algebra_09/soltan-u19/0-1/740-1.webp?ts=1752834734" ] ] ] #original: array:7 [ "id" => 1277095 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1159} "task" => array:2 [ "refs" => "1108482" "type" => "task" ] "text" => "<p><strong>740.</strong> Преобразуйте в произведение выражение:</p><p><strong>а)</strong> $ \sin 20^\circ + \sin 40^\circ $;</p><p><strong>б)</strong> $ \sin 55^\circ - \sin(-65^\circ) $;</p><p><strong>в)</strong> $ \cos 12^\circ + \sin 42^\circ $;</p><p><strong>г)</strong> $ \cos(-50^\circ) - \sin 20^\circ $;</p><p><strong>д)</strong> $ \sin 255^\circ - \sin 165^\circ $;</p><p><strong>е)</strong> $ \cos 315^\circ + \cos 225^\circ $.</p>" "img" => array:1 [ 0 => array:5 [ "name" => "740-1.jpg" "alt" => null "width" => "1139" "height" => 323 "path" => "/media/algebra_09/soltan-u19/0-1/740-1.webp?ts=1752834734" ] ] ] #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 {#1157 #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" => 1278386 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1167 #items: array:1 [ 0 => App\Models\Edition {#1158 #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" => 4954 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Решение" "field_order" => "2" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1161 …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" => "1-" "field_responsible" => Illuminate\Database\Eloquent\Collection {#1162 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1163 …2} "field_process_formula" => "" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1164 …2} "field_content_source" => null ] #original: array:21 [ "id" => 4954 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Решение" "field_order" => "2" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1161 …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" => "1-" "field_responsible" => Illuminate\Database\Eloquent\Collection {#1162 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1163 …2} "field_process_formula" => "" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1164 …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" => "1108482" "type" => "task" ] "img" => array:1 [ 0 => array:5 [ "name" => "740-1.jpg" "alt" => null "width" => "1455" "height" => 1238 "path" => "/media/algebra_09/soltan-u19/1-1/740-1.webp?ts=1752831534" ] ] ] #original: array:6 [ "id" => 1278386 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1167} "task" => array:2 [ "refs" => "1108482" "type" => "task" ] "img" => array:1 [ 0 => array:5 [ "name" => "740-1.jpg" "alt" => null "width" => "1455" "height" => 1238 "path" => "/media/algebra_09/soltan-u19/1-1/740-1.webp?ts=1752831534" ] ] ] #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 {#1165 #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" => 1554341 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1175 #items: array:1 [ 0 => App\Models\Edition {#1166 #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" => 5665 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Решение 2 (rus)" "field_order" => "3" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1169 …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" => "tolik" "field_edition_type" => "solution" "field_root_dir" => "2-" "field_responsible" => Illuminate\Database\Eloquent\Collection {#1170 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1171 …2} "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1172 …2} "field_content_source" => null ] #original: array:21 [ "id" => 5665 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "title" => "Решение 2 (rus)" "field_order" => "3" "field_publisher" => Illuminate\Database\Eloquent\Collection {#1169 …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" => "tolik" "field_edition_type" => "solution" "field_root_dir" => "2-" "field_responsible" => Illuminate\Database\Eloquent\Collection {#1170 …2} "field_comment" => null "field_similar_book" => Illuminate\Database\Eloquent\Collection {#1171 …2} "field_process_formula" => "katex" "field_edition_group" => Illuminate\Database\Eloquent\Collection {#1172 …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" => "1108482" "type" => "task" ] "text" => "<p><strong>а)</strong> Для преобразования выражения $sin 20^\circ + sin 40^\circ$ используем формулу суммы синусов: $sin \alpha + sin \beta = 2 sin(\frac{\alpha+\beta}{2}) cos(\frac{\alpha-\beta}{2})$.</p><p>В нашем случае $\alpha = 20^\circ$ и $\beta = 40^\circ$:</p><p>$sin 20^\circ + sin 40^\circ = 2 sin(\frac{20^\circ+40^\circ}{2}) cos(\frac{20^\circ-40^\circ}{2}) = 2 sin(\frac{60^\circ}{2}) cos(\frac{-20^\circ}{2}) = 2 sin(30^\circ) cos(-10^\circ)$.</p><p>Используя свойство четности косинуса $cos(-x) = cos(x)$ и значение $sin(30^\circ) = \frac{1}{2}$, получаем:</p><p>$2 sin(30^\circ) cos(10^\circ) = 2 \cdot \frac{1}{2} \cdot cos(10^\circ) = cos(10^\circ)$.</p><p><strong>Ответ:</strong> $cos(10^\circ)$.</p><p><strong>б)</strong> Сначала упростим выражение, используя свойство нечетности синуса $sin(-x) = -sin(x)$:</p><p>$sin 55^\circ - sin(-65^\circ) = sin 55^\circ - (-sin 65^\circ) = sin 55^\circ + sin 65^\circ$.</p><p>Теперь применяем формулу суммы синусов $sin \alpha + sin \beta = 2 sin(\frac{\alpha+\beta}{2}) cos(\frac{\alpha-\beta}{2})$:</p><p>$sin 55^\circ + sin 65^\circ = 2 sin(\frac{55^\circ+65^\circ}{2}) cos(\frac{55^\circ-65^\circ}{2}) = 2 sin(\frac{120^\circ}{2}) cos(\frac{-10^\circ}{2}) = 2 sin(60^\circ) cos(-5^\circ)$.</p><p>Так как $cos(-5^\circ) = cos(5^\circ)$ и $sin(60^\circ) = \frac{\sqrt{3}}{2}$, получаем:</p><p>$2 \cdot \frac{\sqrt{3}}{2} \cdot cos(5^\circ) = \sqrt{3} cos(5^\circ)$.</p><p><strong>Ответ:</strong> $\sqrt{3} cos(5^\circ)$.</p><p><strong>в)</strong> В выражении $cos 12^\circ + sin 42^\circ$ приведем функции к одному наименованию, используя формулу приведения $sin \alpha = cos(90^\circ - \alpha)$:</p><p>$sin 42^\circ = cos(90^\circ - 42^\circ) = cos(48^\circ)$.</p><p>Выражение принимает вид: $cos 12^\circ + cos 48^\circ$.</p><p>Применяем формулу суммы косинусов $cos \alpha + cos \beta = 2 cos(\frac{\alpha+\beta}{2}) cos(\frac{\alpha-\beta}{2})$:</p><p>$cos 12^\circ + cos 48^\circ = 2 cos(\frac{12^\circ+48^\circ}{2}) cos(\frac{12^\circ-48^\circ}{2}) = 2 cos(\frac{60^\circ}{2}) cos(\frac{-36^\circ}{2}) = 2 cos(30^\circ) cos(-18^\circ)$.</p><p>Используя $cos(-18^\circ) = cos(18^\circ)$ и $cos(30^\circ) = \frac{\sqrt{3}}{2}$, получаем:</p><p>$2 \cdot \frac{\sqrt{3}}{2} \cdot cos(18^\circ) = \sqrt{3} cos(18^\circ)$.</p><p><strong>Ответ:</strong> $\sqrt{3} cos(18^\circ)$.</p><p><strong>г)</strong> Сначала упростим выражение, используя свойство четности косинуса $cos(-x) = cos(x)$:</p><p>$cos(-50^\circ) - sin 20^\circ = cos 50^\circ - sin 20^\circ$.</p><p>Приведем функции к одному наименованию, используя формулу приведения $sin \alpha = cos(90^\circ - \alpha)$:</p><p>$sin 20^\circ = cos(90^\circ - 20^\circ) = cos(70^\circ)$.</p><p>Выражение принимает вид: $cos 50^\circ - cos 70^\circ$.</p><p>Применяем формулу разности косинусов $cos \alpha - cos \beta = -2 sin(\frac{\alpha+\beta}{2}) sin(\frac{\alpha-\beta}{2})$:</p><p>$cos 50^\circ - cos 70^\circ = -2 sin(\frac{50^\circ+70^\circ}{2}) sin(\frac{50^\circ-70^\circ}{2}) = -2 sin(\frac{120^\circ}{2}) sin(\frac{-20^\circ}{2}) = -2 sin(60^\circ) sin(-10^\circ)$.</p><p>Используя $sin(-10^\circ) = -sin(10^\circ)$ и $sin(60^\circ) = \frac{\sqrt{3}}{2}$, получаем:</p><p>$-2 \cdot \frac{\sqrt{3}}{2} \cdot (-sin 10^\circ) = \sqrt{3} sin(10^\circ)$.</p><p><strong>Ответ:</strong> $\sqrt{3} sin(10^\circ)$.</p><p><strong>д)</strong> Для преобразования выражения $sin 255^\circ - sin 165^\circ$ используем формулу разности синусов: $sin \alpha - sin \beta = 2 sin(\frac{\alpha-\beta}{2}) cos(\frac{\alpha+\beta}{2})$.</p><p>Подставляя $\alpha = 255^\circ$ и $\beta = 165^\circ$, получаем:</p><p>$2 sin(\frac{255^\circ-165^\circ}{2}) cos(\frac{255^\circ+165^\circ}{2}) = 2 sin(\frac{90^\circ}{2}) cos(\frac{420^\circ}{2}) = 2 sin(45^\circ) cos(210^\circ)$.</p><p>Так как $sin(45^\circ) = \frac{\sqrt{2}}{2}$ и $cos(210^\circ) = cos(180^\circ + 30^\circ) = -cos(30^\circ) = -\frac{\sqrt{3}}{2}$, то:</p><p>$2 \cdot \frac{\sqrt{2}}{2} \cdot (-\frac{\sqrt{3}}{2}) = \sqrt{2} \cdot (-\frac{\sqrt{3}}{2}) = -\frac{\sqrt{6}}{2}$.</p><p><strong>Ответ:</strong> $-\frac{\sqrt{6}}{2}$.</p><p><strong>е)</strong> Для преобразования выражения $cos 315^\circ + cos 225^\circ$ используем формулу суммы косинусов: $cos \alpha + cos \beta = 2 cos(\frac{\alpha+\beta}{2}) cos(\frac{\alpha-\beta}{2})$.</p><p>Подставляя $\alpha = 315^\circ$ и $\beta = 225^\circ$, получаем:</p><p>$2 cos(\frac{315^\circ+225^\circ}{2}) cos(\frac{315^\circ-225^\circ}{2}) = 2 cos(\frac{540^\circ}{2}) cos(\frac{90^\circ}{2}) = 2 cos(270^\circ) cos(45^\circ)$.</p><p>Так как $cos(270^\circ) = 0$, то значение всего произведения равно нулю:</p><p>$2 \cdot 0 \cdot \frac{\sqrt{2}}{2} = 0$.</p><p><strong>Ответ:</strong> $0$.</p>" ] #original: array:6 [ "id" => 1554341 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1175} "task" => array:2 [ "refs" => "1108482" "type" => "task" ] "text" => "<p><strong>а)</strong> Для преобразования выражения $sin 20^\circ + sin 40^\circ$ используем формулу суммы синусов: $sin \alpha + sin \beta = 2 sin(\frac{\alpha+\beta}{2}) cos(\frac{\alpha-\beta}{2})$.</p><p>В нашем случае $\alpha = 20^\circ$ и $\beta = 40^\circ$:</p><p>$sin 20^\circ + sin 40^\circ = 2 sin(\frac{20^\circ+40^\circ}{2}) cos(\frac{20^\circ-40^\circ}{2}) = 2 sin(\frac{60^\circ}{2}) cos(\frac{-20^\circ}{2}) = 2 sin(30^\circ) cos(-10^\circ)$.</p><p>Используя свойство четности косинуса $cos(-x) = cos(x)$ и значение $sin(30^\circ) = \frac{1}{2}$, получаем:</p><p>$2 sin(30^\circ) cos(10^\circ) = 2 \cdot \frac{1}{2} \cdot cos(10^\circ) = cos(10^\circ)$.</p><p><strong>Ответ:</strong> $cos(10^\circ)$.</p><p><strong>б)</strong> Сначала упростим выражение, используя свойство нечетности синуса $sin(-x) = -sin(x)$:</p><p>$sin 55^\circ - sin(-65^\circ) = sin 55^\circ - (-sin 65^\circ) = sin 55^\circ + sin 65^\circ$.</p><p>Теперь применяем формулу суммы синусов $sin \alpha + sin \beta = 2 sin(\frac{\alpha+\beta}{2}) cos(\frac{\alpha-\beta}{2})$:</p><p>$sin 55^\circ + sin 65^\circ = 2 sin(\frac{55^\circ+65^\circ}{2}) cos(\frac{55^\circ-65^\circ}{2}) = 2 sin(\frac{120^\circ}{2}) cos(\frac{-10^\circ}{2}) = 2 sin(60^\circ) cos(-5^\circ)$.</p><p>Так как $cos(-5^\circ) = cos(5^\circ)$ и $sin(60^\circ) = \frac{\sqrt{3}}{2}$, получаем:</p><p>$2 \cdot \frac{\sqrt{3}}{2} \cdot cos(5^\circ) = \sqrt{3} cos(5^\circ)$.</p><p><strong>Ответ:</strong> $\sqrt{3} cos(5^\circ)$.</p><p><strong>в)</strong> В выражении $cos 12^\circ + sin 42^\circ$ приведем функции к одному наименованию, используя формулу приведения $sin \alpha = cos(90^\circ - \alpha)$:</p><p>$sin 42^\circ = cos(90^\circ - 42^\circ) = cos(48^\circ)$.</p><p>Выражение принимает вид: $cos 12^\circ + cos 48^\circ$.</p><p>Применяем формулу суммы косинусов $cos \alpha + cos \beta = 2 cos(\frac{\alpha+\beta}{2}) cos(\frac{\alpha-\beta}{2})$:</p><p>$cos 12^\circ + cos 48^\circ = 2 cos(\frac{12^\circ+48^\circ}{2}) cos(\frac{12^\circ-48^\circ}{2}) = 2 cos(\frac{60^\circ}{2}) cos(\frac{-36^\circ}{2}) = 2 cos(30^\circ) cos(-18^\circ)$.</p><p>Используя $cos(-18^\circ) = cos(18^\circ)$ и $cos(30^\circ) = \frac{\sqrt{3}}{2}$, получаем:</p><p>$2 \cdot \frac{\sqrt{3}}{2} \cdot cos(18^\circ) = \sqrt{3} cos(18^\circ)$.</p><p><strong>Ответ:</strong> $\sqrt{3} cos(18^\circ)$.</p><p><strong>г)</strong> Сначала упростим выражение, используя свойство четности косинуса $cos(-x) = cos(x)$:</p><p>$cos(-50^\circ) - sin 20^\circ = cos 50^\circ - sin 20^\circ$.</p><p>Приведем функции к одному наименованию, используя формулу приведения $sin \alpha = cos(90^\circ - \alpha)$:</p><p>$sin 20^\circ = cos(90^\circ - 20^\circ) = cos(70^\circ)$.</p><p>Выражение принимает вид: $cos 50^\circ - cos 70^\circ$.</p><p>Применяем формулу разности косинусов $cos \alpha - cos \beta = -2 sin(\frac{\alpha+\beta}{2}) sin(\frac{\alpha-\beta}{2})$:</p><p>$cos 50^\circ - cos 70^\circ = -2 sin(\frac{50^\circ+70^\circ}{2}) sin(\frac{50^\circ-70^\circ}{2}) = -2 sin(\frac{120^\circ}{2}) sin(\frac{-20^\circ}{2}) = -2 sin(60^\circ) sin(-10^\circ)$.</p><p>Используя $sin(-10^\circ) = -sin(10^\circ)$ и $sin(60^\circ) = \frac{\sqrt{3}}{2}$, получаем:</p><p>$-2 \cdot \frac{\sqrt{3}}{2} \cdot (-sin 10^\circ) = \sqrt{3} sin(10^\circ)$.</p><p><strong>Ответ:</strong> $\sqrt{3} sin(10^\circ)$.</p><p><strong>д)</strong> Для преобразования выражения $sin 255^\circ - sin 165^\circ$ используем формулу разности синусов: $sin \alpha - sin \beta = 2 sin(\frac{\alpha-\beta}{2}) cos(\frac{\alpha+\beta}{2})$.</p><p>Подставляя $\alpha = 255^\circ$ и $\beta = 165^\circ$, получаем:</p><p>$2 sin(\frac{255^\circ-165^\circ}{2}) cos(\frac{255^\circ+165^\circ}{2}) = 2 sin(\frac{90^\circ}{2}) cos(\frac{420^\circ}{2}) = 2 sin(45^\circ) cos(210^\circ)$.</p><p>Так как $sin(45^\circ) = \frac{\sqrt{2}}{2}$ и $cos(210^\circ) = cos(180^\circ + 30^\circ) = -cos(30^\circ) = -\frac{\sqrt{3}}{2}$, то:</p><p>$2 \cdot \frac{\sqrt{2}}{2} \cdot (-\frac{\sqrt{3}}{2}) = \sqrt{2} \cdot (-\frac{\sqrt{3}}{2}) = -\frac{\sqrt{6}}{2}$.</p><p><strong>Ответ:</strong> $-\frac{\sqrt{6}}{2}$.</p><p><strong>е)</strong> Для преобразования выражения $cos 315^\circ + cos 225^\circ$ используем формулу суммы косинусов: $cos \alpha + cos \beta = 2 cos(\frac{\alpha+\beta}{2}) cos(\frac{\alpha-\beta}{2})$.</p><p>Подставляя $\alpha = 315^\circ$ и $\beta = 225^\circ$, получаем:</p><p>$2 cos(\frac{315^\circ+225^\circ}{2}) cos(\frac{315^\circ-225^\circ}{2}) = 2 cos(\frac{540^\circ}{2}) cos(\frac{90^\circ}{2}) = 2 cos(270^\circ) cos(45^\circ)$.</p><p>Так как $cos(270^\circ) = 0$, то значение всего произведения равно нулю:</p><p>$2 \cdot 0 \cdot \frac{\sqrt{2}}{2} = 0$.</p><p><strong>Ответ:</strong> $0$.</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" => "1108483" "type" => "task" ] "previous" => array:2 [ "refs" => "1108481" "type" => "task" ] "book" => Illuminate\Database\Eloquent\Collection {#1195 #items: array:1 [ 0 => App\Models\Book {#1147 #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" => 4298 "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 {#1140 #items: array:1 [ 0 => App\Models\Term {#1139 #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" => 6471 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Алгебра" "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" => "algebra" ] #original: array:10 [ "id" => 6471 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Алгебра" "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" => "algebra" ] #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 {#1146 #items: array:1 [ 0 => App\Models\Term {#1148 #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" => 5458 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "9" "field_cases" => array:6 [ …6] "field_translit" => "devjatyj" ] #original: array:6 [ "id" => 5458 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "9" "field_cases" => array:6 [ …6] "field_translit" => "devjatyj" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_publisher" => Illuminate\Database\Eloquent\Collection {#1144 #items: array:1 [ 0 => 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:6 [ "id" => 7002 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Кокшетау" "field_cases" => array:6 [ …6] "field_translit" => "Kokshetau" ] #original: array:6 [ "id" => 7002 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Кокшетау" "field_cases" => array:6 [ …6] "field_translit" => "Kokshetau" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_author" => Illuminate\Database\Eloquent\Collection {#1145 #items: array:3 [ 0 => App\Models\Term {#1143 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:12 [ "id" => 7003 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Солтан" "field_bio" => null "field_degree_rp" => null "field_foreign_lang_name" => null "field_foreign_lang_patronymic" => null "field_foreign_lang_surname" => null "field_name" => "Генадий" "field_patronymic" => "Николаевич" "field_surname_rp" => null ] #original: array:12 [ "id" => 7003 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Солтан" "field_bio" => null "field_degree_rp" => null "field_foreign_lang_name" => null "field_foreign_lang_patronymic" => null "field_foreign_lang_surname" => null "field_name" => "Генадий" "field_patronymic" => "Николаевич" "field_surname_rp" => null ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 1 => App\Models\Term {#1173 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:12 [ "id" => 7004 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Солтан" "field_bio" => null "field_degree_rp" => null "field_foreign_lang_name" => null "field_foreign_lang_patronymic" => null "field_foreign_lang_surname" => null "field_name" => "Алла" "field_patronymic" => "Евгеньевна" "field_surname_rp" => null ] #original: array:12 [ "id" => 7004 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Солтан" "field_bio" => null "field_degree_rp" => null "field_foreign_lang_name" => null "field_foreign_lang_patronymic" => null "field_foreign_lang_surname" => null "field_name" => "Алла" "field_patronymic" => "Евгеньевна" "field_surname_rp" => null ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 2 => App\Models\Term {#1174 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:12 [ "id" => 7005 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Жумадилова" "field_bio" => null "field_degree_rp" => null "field_foreign_lang_name" => null "field_foreign_lang_patronymic" => null "field_foreign_lang_surname" => null "field_name" => "Аманбала" "field_patronymic" => "Жумадиловна" "field_surname_rp" => null ] #original: array:12 [ "id" => 7005 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Жумадилова" "field_bio" => null "field_degree_rp" => null "field_foreign_lang_name" => null "field_foreign_lang_patronymic" => null "field_foreign_lang_surname" => null "field_name" => "Аманбала" "field_patronymic" => "Жумадиловна" "field_surname_rp" => null ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1176 #items: [] #escapeWhenCastingToString: false } "field_book_type" => Illuminate\Database\Eloquent\Collection {#1177 #items: array:1 [ 0 => App\Models\Term {#1178 #connection: "mysql" #table: "terms" #primaryKey: "id" #keyType: "int" +incrementing: false #with: [] #withCount: [] +preventsLazyLoading: false #perPage: 15 +exists: true +wasRecentlyCreated: false #escapeWhenCastingToString: false #attributes: array:10 [ "id" => 6671 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Учебник" "field_book_type_foreign" => null "field_cases" => array:6 [ …6] "field_plural_form" => null "field_short_name" => null "field_short_name_foreign" => null "field_translit" => "uchebnik" ] #original: array:10 [ "id" => 6671 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Учебник" "field_book_type_foreign" => null "field_cases" => array:6 [ …6] "field_plural_form" => null "field_short_name" => null "field_short_name_foreign" => null "field_translit" => "uchebnik" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_country" => Illuminate\Database\Eloquent\Collection {#1179 #items: array:1 [ 0 => App\Models\Term {#1180 #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" => 6994 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Казахстан" "field_cases" => array:6 [ …6] "field_translit" => "kazakhstan" ] #original: array:6 [ "id" => 6994 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Казахстан" "field_cases" => array:6 [ …6] "field_translit" => "kazakhstan" ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } ] #escapeWhenCastingToString: false } "field_city" => Illuminate\Database\Eloquent\Collection {#1181 #items: array:1 [ 0 => App\Models\Term {#1182 #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" => 6995 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Алматы" "field_cases" => array:6 [ …6] "field_translit" => "almaty" ] #original: array:6 [ "id" => 6995 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "name" => "Алматы" "field_cases" => array:6 [ …6] "field_translit" => "almaty" ] #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_series" => Illuminate\Database\Eloquent\Collection {#1183 #items: [] #escapeWhenCastingToString: false } "field_umk" => Illuminate\Database\Eloquent\Collection {#1184 #items: [] #escapeWhenCastingToString: false } "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1185 #items: [] #escapeWhenCastingToString: false } "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1186 #items: [] #escapeWhenCastingToString: false } "field_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1187 #items: [] #escapeWhenCastingToString: false } "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1188 #items: [] #escapeWhenCastingToString: false } "field_under_the_edition_degree" => null "field_cover_description" => null "field_publication_year" => "2019" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебник для учащихся 9 класса общеобразовательных школ" "field_allowed" => "Рекомендовано Министерством образования и науки Республики Казахстан" "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "1291" "field_priority" => "4" "field_default_folder" => "/algebra_09/soltan-u19/" "field_isbn" => "978-601-317-424-2" "field_cover" => array:1 [ 0 => "/media/algebra_09/soltan-u19/covers/cover1.webp?ts=1752140452" ] "field_cover_alts" => array:1 [ 0 => "" ] "field_covers" => array:1 [ 0 => array:4 [ "path" => "/media/algebra_09/soltan-u19/covers/cover1.webp?ts=1752140452" "alt" => "" "width" => "1940" "height" => "2895" ] ] "field_popular_book" => null "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1189 #items: [] #escapeWhenCastingToString: false } "field_new_book" => Illuminate\Database\Eloquent\Collection {#1190 #items: [] #escapeWhenCastingToString: false } "field_old_book" => Illuminate\Database\Eloquent\Collection {#1191 #items: [] #escapeWhenCastingToString: false } "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1192 #items: [] #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" => 380 "subject" => 542 "class_subject" => 386 ] ] #original: array:50 [ "id" => 4298 "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 {#1140} "field_class" => Illuminate\Database\Eloquent\Collection {#1146} "field_publisher" => Illuminate\Database\Eloquent\Collection {#1144} "field_author" => Illuminate\Database\Eloquent\Collection {#1145} "field_author_foreign" => Illuminate\Database\Eloquent\Collection {#1176} "field_book_type" => Illuminate\Database\Eloquent\Collection {#1177} "field_country" => Illuminate\Database\Eloquent\Collection {#1179} "field_city" => Illuminate\Database\Eloquent\Collection {#1181} "field_series" => Illuminate\Database\Eloquent\Collection {#1183} "field_umk" => Illuminate\Database\Eloquent\Collection {#1184} "field_level_of_education" => Illuminate\Database\Eloquent\Collection {#1185} "field_standart_of_education" => Illuminate\Database\Eloquent\Collection {#1186} "field_publication_number" => null "field_publication_type" => Illuminate\Database\Eloquent\Collection {#1187} "field_under_the_edition" => Illuminate\Database\Eloquent\Collection {#1188} "field_under_the_edition_degree" => null "field_cover_description" => null "field_publication_year" => "2019" "field_publication_year_until" => null "field_part" => "" "field_part_writing" => "" "field_second_foreign_language" => null "field_for_whom" => "Учебник для учащихся 9 класса общеобразовательных школ" "field_allowed" => "Рекомендовано Министерством образования и науки Республики Казахстан" "field_reserve_field" => null "field_link_to_source" => null "field_tasks_count" => "1291" "field_priority" => "4" "field_default_folder" => "/algebra_09/soltan-u19/" "field_isbn" => "978-601-317-424-2" "field_cover" => array:1 [ 0 => "/media/algebra_09/soltan-u19/covers/cover1.webp?ts=1752140452" ] "field_cover_alts" => array:1 [ 0 => "" ] "field_covers" => array:1 [ 0 => array:4 [ "path" => "/media/algebra_09/soltan-u19/covers/cover1.webp?ts=1752140452" "alt" => "" "width" => "1940" "height" => "2895" ] ] "field_popular_book" => null "field_recommended_books" => Illuminate\Database\Eloquent\Collection {#1189} "field_new_book" => Illuminate\Database\Eloquent\Collection {#1190} "field_old_book" => Illuminate\Database\Eloquent\Collection {#1191} "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik" "field_cover_color" => Illuminate\Database\Eloquent\Collection {#1192} "field_metatags_title" => null "field_metatags_description" => null "field_h1" => null "field_description_top" => null "field_description_bottom" => null "breadcrumbs" => array:3 [ "class" => 380 "subject" => 542 "class_subject" => 386 ] ] #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 {#1200 #items: array:1 [ 0 => App\Models\BookPage {#1199 #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" => 1097954 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "212" "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik/page-212" "field_display_title" => "212" "field_folder" => "folder1" "field_image_name" => "212" "field_branch_parent" => Illuminate\Database\Eloquent\Collection {#1201 #items: [] #escapeWhenCastingToString: false } "field_weight" => "0" "field_book_parent" => Illuminate\Database\Eloquent\Collection {#1202 #items: array:1 [ 0 => App\Models\Book {#1147} ] #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 {#1203 #items: [] #escapeWhenCastingToString: false } "content" => Illuminate\Database\Eloquent\Collection {#1213 #items: array:1 [ 0 => App\Models\Element {#1212 #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" => 1261105 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1214 …2} "book_page" => array:2 [ …2] "img" => array:1 [ …1] ] #original: array:6 [ "id" => 1261105 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "edition" => Illuminate\Database\Eloquent\Collection {#1214 …2} "book_page" => array:2 [ …2] "img" => array:1 [ …1] ] #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" => "1097955" "type" => "book_page" ] "previous" => array:2 [ "refs" => "1097953" "type" => "book_page" ] "tasks" => Illuminate\Database\Eloquent\Collection {#1370 #items: array:6 [ 0 => App\Models\Task {#1382 #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" => 1108480 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "212" "field_page_end" => null "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik/1-738" "field_display_title" => "738" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1383 …2} "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 {#1384 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1385 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1386 …2} "content" => Illuminate\Database\Eloquent\Collection {#1389 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1395 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1108480 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "212" "field_page_end" => null "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik/1-738" "field_display_title" => "738" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1383 …2} "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 {#1384 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1385 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1386 …2} "content" => Illuminate\Database\Eloquent\Collection {#1389 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1395 …2} "page" => array:2 [ …2] ] #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\Task {#1388 #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" => 1108481 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "212" "field_page_end" => null "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik/1-739" "field_display_title" => "739" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1387 …2} "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 {#1394 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1396 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1392 …2} "content" => Illuminate\Database\Eloquent\Collection {#1391 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1409 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1108481 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "212" "field_page_end" => null "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik/1-739" "field_display_title" => "739" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1387 …2} "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 {#1394 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1396 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1392 …2} "content" => Illuminate\Database\Eloquent\Collection {#1391 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1409 …2} "page" => array:2 [ …2] ] #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\Task {#1393 #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" => 1108482 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "212" "field_page_end" => null "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik/1-740" "field_display_title" => "740" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1390 …2} "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 {#1408 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1410 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1406 …2} "content" => Illuminate\Database\Eloquent\Collection {#1404 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1407 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1108482 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "212" "field_page_end" => null "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik/1-740" "field_display_title" => "740" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1390 …2} "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 {#1408 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1410 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1406 …2} "content" => Illuminate\Database\Eloquent\Collection {#1404 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1407 …2} "page" => array:2 [ …2] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 3 => App\Models\Task {#1405 #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" => 1108483 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "212" "field_page_end" => null "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik/1-741" "field_display_title" => "741" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1418 …2} "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 {#1419 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1420 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1421 …2} "content" => Illuminate\Database\Eloquent\Collection {#1424 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1430 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1108483 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "212" "field_page_end" => null "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik/1-741" "field_display_title" => "741" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1418 …2} "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 {#1419 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1420 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1421 …2} "content" => Illuminate\Database\Eloquent\Collection {#1424 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1430 …2} "page" => array:2 [ …2] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true +usesUniqueIds: false #hidden: [] #visible: [] #fillable: [] #guarded: array:1 [ 0 => "*" ] } 4 => App\Models\Task {#1423 #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" => 1108484 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "212" "field_page_end" => null "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik/1-742" "field_display_title" => "742" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1422 …2} "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 {#1429 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1431 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1427 …2} "content" => Illuminate\Database\Eloquent\Collection {#1426 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1444 …2} "page" => array:2 [ …2] ] #original: array:24 [ "id" => 1108484 "created_at" => "2026-04-10 13:58:26" "updated_at" => null "field_page_start" => "212" "field_page_end" => null "field_url" => "/9-klass/algebra/kokshetau-soltan-uchebnik/1-742" "field_display_title" => "742" "field_outside_task" => null "field_task_type" => Illuminate\Database\Eloquent\Collection {#1422 …2} "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 {#1429 …2} "top_parent_branch" => Illuminate\Database\Eloquent\Collection {#1431 …2} "parent_branches" => Illuminate\Database\Eloquent\Collection {#1427 …2} "content" => Illuminate\Database\Eloquent\Collection {#1426 …2} "next" => array:2 [ …2] "previous" => array:2 [ …2] "book" => Illuminate\Database\Eloquent\Collection {#1444 …2} "page" => array:2 [ …2] ] #changes: [] #casts: [] #classCastCache: [] #attributeCastCache: [] #dateFormat: null #appends: [] #dispatchesEvents: [] #observables: [] #relations: [] #touches: [] +timestamps: true 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№740 (с. 212)
Условие. №740 (с. 212)
скриншот условия
740. Преобразуйте в произведение выражение:
а) $ \sin 20^\circ + \sin 40^\circ $;
б) $ \sin 55^\circ - \sin(-65^\circ) $;
в) $ \cos 12^\circ + \sin 42^\circ $;
г) $ \cos(-50^\circ) - \sin 20^\circ $;
д) $ \sin 255^\circ - \sin 165^\circ $;
е) $ \cos 315^\circ + \cos 225^\circ $.
Решение. №740 (с. 212)
Решение 2 (rus). №740 (с. 212)
а) Для преобразования выражения $sin 20^\circ + sin 40^\circ$ используем формулу суммы синусов: $sin \alpha + sin \beta = 2 sin(\frac{\alpha+\beta}{2}) cos(\frac{\alpha-\beta}{2})$.
В нашем случае $\alpha = 20^\circ$ и $\beta = 40^\circ$:
$sin 20^\circ + sin 40^\circ = 2 sin(\frac{20^\circ+40^\circ}{2}) cos(\frac{20^\circ-40^\circ}{2}) = 2 sin(\frac{60^\circ}{2}) cos(\frac{-20^\circ}{2}) = 2 sin(30^\circ) cos(-10^\circ)$.
Используя свойство четности косинуса $cos(-x) = cos(x)$ и значение $sin(30^\circ) = \frac{1}{2}$, получаем:
$2 sin(30^\circ) cos(10^\circ) = 2 \cdot \frac{1}{2} \cdot cos(10^\circ) = cos(10^\circ)$.
Ответ: $cos(10^\circ)$.
б) Сначала упростим выражение, используя свойство нечетности синуса $sin(-x) = -sin(x)$:
$sin 55^\circ - sin(-65^\circ) = sin 55^\circ - (-sin 65^\circ) = sin 55^\circ + sin 65^\circ$.
Теперь применяем формулу суммы синусов $sin \alpha + sin \beta = 2 sin(\frac{\alpha+\beta}{2}) cos(\frac{\alpha-\beta}{2})$:
$sin 55^\circ + sin 65^\circ = 2 sin(\frac{55^\circ+65^\circ}{2}) cos(\frac{55^\circ-65^\circ}{2}) = 2 sin(\frac{120^\circ}{2}) cos(\frac{-10^\circ}{2}) = 2 sin(60^\circ) cos(-5^\circ)$.
Так как $cos(-5^\circ) = cos(5^\circ)$ и $sin(60^\circ) = \frac{\sqrt{3}}{2}$, получаем:
$2 \cdot \frac{\sqrt{3}}{2} \cdot cos(5^\circ) = \sqrt{3} cos(5^\circ)$.
Ответ: $\sqrt{3} cos(5^\circ)$.
в) В выражении $cos 12^\circ + sin 42^\circ$ приведем функции к одному наименованию, используя формулу приведения $sin \alpha = cos(90^\circ - \alpha)$:
$sin 42^\circ = cos(90^\circ - 42^\circ) = cos(48^\circ)$.
Выражение принимает вид: $cos 12^\circ + cos 48^\circ$.
Применяем формулу суммы косинусов $cos \alpha + cos \beta = 2 cos(\frac{\alpha+\beta}{2}) cos(\frac{\alpha-\beta}{2})$:
$cos 12^\circ + cos 48^\circ = 2 cos(\frac{12^\circ+48^\circ}{2}) cos(\frac{12^\circ-48^\circ}{2}) = 2 cos(\frac{60^\circ}{2}) cos(\frac{-36^\circ}{2}) = 2 cos(30^\circ) cos(-18^\circ)$.
Используя $cos(-18^\circ) = cos(18^\circ)$ и $cos(30^\circ) = \frac{\sqrt{3}}{2}$, получаем:
$2 \cdot \frac{\sqrt{3}}{2} \cdot cos(18^\circ) = \sqrt{3} cos(18^\circ)$.
Ответ: $\sqrt{3} cos(18^\circ)$.
г) Сначала упростим выражение, используя свойство четности косинуса $cos(-x) = cos(x)$:
$cos(-50^\circ) - sin 20^\circ = cos 50^\circ - sin 20^\circ$.
Приведем функции к одному наименованию, используя формулу приведения $sin \alpha = cos(90^\circ - \alpha)$:
$sin 20^\circ = cos(90^\circ - 20^\circ) = cos(70^\circ)$.
Выражение принимает вид: $cos 50^\circ - cos 70^\circ$.
Применяем формулу разности косинусов $cos \alpha - cos \beta = -2 sin(\frac{\alpha+\beta}{2}) sin(\frac{\alpha-\beta}{2})$:
$cos 50^\circ - cos 70^\circ = -2 sin(\frac{50^\circ+70^\circ}{2}) sin(\frac{50^\circ-70^\circ}{2}) = -2 sin(\frac{120^\circ}{2}) sin(\frac{-20^\circ}{2}) = -2 sin(60^\circ) sin(-10^\circ)$.
Используя $sin(-10^\circ) = -sin(10^\circ)$ и $sin(60^\circ) = \frac{\sqrt{3}}{2}$, получаем:
$-2 \cdot \frac{\sqrt{3}}{2} \cdot (-sin 10^\circ) = \sqrt{3} sin(10^\circ)$.
Ответ: $\sqrt{3} sin(10^\circ)$.
д) Для преобразования выражения $sin 255^\circ - sin 165^\circ$ используем формулу разности синусов: $sin \alpha - sin \beta = 2 sin(\frac{\alpha-\beta}{2}) cos(\frac{\alpha+\beta}{2})$.
Подставляя $\alpha = 255^\circ$ и $\beta = 165^\circ$, получаем:
$2 sin(\frac{255^\circ-165^\circ}{2}) cos(\frac{255^\circ+165^\circ}{2}) = 2 sin(\frac{90^\circ}{2}) cos(\frac{420^\circ}{2}) = 2 sin(45^\circ) cos(210^\circ)$.
Так как $sin(45^\circ) = \frac{\sqrt{2}}{2}$ и $cos(210^\circ) = cos(180^\circ + 30^\circ) = -cos(30^\circ) = -\frac{\sqrt{3}}{2}$, то:
$2 \cdot \frac{\sqrt{2}}{2} \cdot (-\frac{\sqrt{3}}{2}) = \sqrt{2} \cdot (-\frac{\sqrt{3}}{2}) = -\frac{\sqrt{6}}{2}$.
Ответ: $-\frac{\sqrt{6}}{2}$.
е) Для преобразования выражения $cos 315^\circ + cos 225^\circ$ используем формулу суммы косинусов: $cos \alpha + cos \beta = 2 cos(\frac{\alpha+\beta}{2}) cos(\frac{\alpha-\beta}{2})$.
Подставляя $\alpha = 315^\circ$ и $\beta = 225^\circ$, получаем:
$2 cos(\frac{315^\circ+225^\circ}{2}) cos(\frac{315^\circ-225^\circ}{2}) = 2 cos(\frac{540^\circ}{2}) cos(\frac{90^\circ}{2}) = 2 cos(270^\circ) cos(45^\circ)$.
Так как $cos(270^\circ) = 0$, то значение всего произведения равно нулю:
$2 \cdot 0 \cdot \frac{\sqrt{2}}{2} = 0$.
Ответ: $0$.
Другие задания:
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