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
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