Sin^2(x) -sin^2(2x) +sin^3(3x) =0.5 решить

Решение.
(sin(2x))^2+(sin(3x))^2+(sin(4x))^2+(sin(5x))^2=2
(1-cos(4x))/2+(1-cos(6x)/2+(1-cos(8x))/2+(1-cos(10x)/2=2
cos(4x)+cos(6x)+cos(8x)+cos(10x)=0
2*cos(6x)*cos(2x)+2*cos(8x)*c0s(2x)=0
Cos(2x)*(cos(6x)+cos(8x))=0
2*cos(x)*cos(2x)*cos(7x)=0
cos(x)=0 x1=п/2+пk k Є Z
cos(2x)=0 2x=п/2+пm x2=п/4+пm/2 m Є Z
cos(7x)=0 7x=п/2+пl x3=п/14+пl/7 l Є Z
ответ: x1=п/4+пm/2 m Є Z, x2=п/14+пk/7 k Є Z