cos2x+cos(п/2+x)+1=cos^2п/3+cos^2п/6 найдите плизз

cos(2x) - sin(x) = (cos(p-p/3))^2 + 3/4
1 - 2sin^2(x) - sin(x) = 1/4 + 3/4
2sin^2(x) + sin(x) = 0
sin(x)(2sin(x) + 1) = 0
sin(x) = 0
x1 = pk, k E Z
2sin(x) + 1 = 0
sin(x) = -1/2
x2 = (-1)^(k+1) p/6 + pk, k E Z