Решитте уравнение: 4cos^3x=sin(x-3п\2)

4 cos^3x = sin(х-3π/2)

4 cos^3x = -sin(3π/2 - х)

4 cos^3x = сosх

cos^2x = 1/4

1) cosx = 1/2                                 2) cosx = -1/2  

х1 = ±π/3 + 2πn   n∈Z                   х2= ±2π/3 + 2πn   n∈Z