1.Sin-(x)=sin 2пи
2.Sin(пи/2-x)=sin пи/4

1. sin(-x) = sin(2π)sin(-x) = 0-x = πn, n ∈ Zx=-πn, n ∈ Z2. sin(π/2-x)=sin(π/4)sin(π/2-x) = sqrt(2)/2π/2-x = π/4 + 2πn, n∈Z и 3π/4 + 2πn-x = -π/4 + 2πn и π/4 + 2πn, n∈Zx = +- π/4 + 2πn, n∈Z