f'(x)=1/2+cos(x-Pi/3)
1/2+cos(x-Pi/3) = 0
cos(x-Pi/3) = -1/2
x - Pi/3 = +- arccos(-1/2) + 2Pi*k, k прин Z
x - Pi/3 = +- (Pi - arccos(1/2)) + 2Pi*k, k прин Z
x - Pi/3 = +- (Pi - Pi/3) + 2Pi*k, k прин Z
x - Pi/3 = +- (2Pi/3) + 2Pi*k, k прин Z
x = +- (2Pi/3) + Pi/3 + 2Pi*k, k прин Z