6х = (-1)^n arcSin(-1/2) + nπ, n∈Z
6x = (-1)^n (-π/6) + πn, n∈Z
6x = (-1)^(n+1)·π/6 + π n, n∈Z
x = (-1)^(n + 1) ·π/36 + πn/6, n ∈Z
