Решить уравнение cos^3x=(1-sin^2x)/(2sinx)

Cos^3 (x)* 2sin(x) = 1-sin^2 (x)
2cos(x)*sin(x)*cos^2 (x) = cos^2 (x)
sin(2x)* cos^2 (x) - cos^2 (x) = 0
cos^2 (x)* (sin (2x) - 1) = 0
cos^2 (x) = 0 или  sin2x - 1 = 0
cos x = 0              sin2x = 1
x= π/2 + πn          2x = π/2  +2πk
                            x = π/4 + πk