1) Cos² x + Cos x Sin x = 0 |: Сos²x ≠ 0
1 + tg x = 0
tg x = -1
x = -π/4 + πk , k ∈Z
2) а) Sin(arcCos√2/2) -2arcSin0 = Sin π/4 -2·0 = √2/2
б) Ctg(6arcCtg(-√3/2) = Ctg(6(π - arcCtg√3/2) =
=Ctg(6π - arcCtg√3/2) = - Ctg(arcCtg√3/2) = -√3/2
3)Sin(3π/2 + 5x) = 1/2
-Cos 5x = 1/2
Cos 5x = -1/2
5x = +-arcCos(-1/2 ) +2πk, k ∈Z
5x = =-2π/3 + 2πk , k∈Z
x = +-2π/15 + 2πk/5, k ∈Z