![Kulasius](https://sproshu.net/uploads/ava/1/ava475.jpg)
Kulasius
6 год назад
Найдите значение выражения
![](https://store.sproshu.net/2/7ddc7ac89998d7.jpg)
ОТВЕТЫ
![Флорентий](https://sproshu.net/uploads/ava/4/ava5064.jpg)
Флорентий
Jun 30, 2019
Решение
1 + cos(x + π/2) + cos(x - π/2) =
= 1 - sinx - sinx = 1 - 2sinx
при x = 5π/12
1 - 2sinx = 1 - 2sin(5π/12) = 1 - 2sin75° = 1 - 2 * 1/2= 1 -1/2= 1/2
1 + cos(x + π/2) + cos(x - π/2) =
= 1 - sinx - sinx = 1 - 2sinx
при x = 5π/12
1 - 2sinx = 1 - 2sin(5π/12) = 1 - 2sin75° = 1 - 2 * 1/2= 1 -1/2= 1/2
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