Question

Тригонометрия
Упростить
1-sin( a/2-3n)-cos^2a....

С решением)))

Answer 1

1 - sin(α/2 - 3π) - cos²α/4 + sin²α/4 = sin²α/4 + cos²α/4 + sin(3π - α/2) - cos²α/4 + sin²α/4 = 2·sin²α/4 + sin α/2 = 2sin²α/4 + 2·sin α/4·cos  α/4 = 2·sin α/4·(sin α/4 + cos  α/4)

cos²(π + α/4)(1 + tg²(3α/4 - 3π/2))/(sin⁻¹(9π/2 + α/2)(tg²(5π/2 - α/4) - tg²(3α/4 - 7π/2))) = cos²α/4·(1 + ctg²3α/4)·cos α/2/(ctg²α/4 - ctg²3α/4) = cos²α/4·cos α/2/(sin²3α/4·(1/sin²α/4 - 1 - (1/sin²3α/4 - 1))) = cos²α/4·cos α/2/(sin²3α/4·(1/sin²α/4 - 1/sin²3α/4)) = cos²α/4·cos α/2/(sin²3α/4 / sin²α/4 - 1) = sin²α/4·cos²α/4·cos α/2/(sin²3α/4 - sin²α/4) = sin²α/4·cos²α/4·cos α/2/((sin 3α/4 - sin α/4)(sin 3α/4 + sin α/4)) = sin²α/4·cos²α/4·cos α/2/(2·sinα/4·cos α/2·2·sin α/2·cos α/4) = sin α/4·cos α/4 / (4·sin α/2) = sin α/4·cos α/4 / (8·sin α/4·cos α/4) = 1/8