Решить уравнение 2(sin^2x-cos^2x)=1
-2Cos2x = 1 Cos2x = -1/2 2х = +-arcCos(-1/2) + 2πk , k ∈ Z 2x = +- 2π/3 + 2πk , k ∈Z x = +-π/3 + 2πk/3, k ∈Z