Предмет: Геометрия, автор: lionmartin99

найти cos а если sin a = 0.8 и 90°

Ответы

Автор ответа: Ердеш

если α лежит от 0 до π/2 и от 3π/2 до 0, то cosα=0.6
если от π/2 до π и от π до 3π/2, то cosα=-0.6

Автор ответа: Ердеш

но поскольку синус положительный, то ответ будет лежать в интервале от 0 до π

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