1+sinx(cos^2 x - sin^2 x) = sin x + cos^2 x - sin^2 x
1 + sin x cos^2 x-sin^3 x=sinx(1 - sinx) + cos^2 x
1 - sin^3 x - sin x (1-sinx)=cos^2 x - sin x*cos^2 x
1 - sin^3 x = cos^2 x(1-sinx)+sinx*(1-sin x)
(1-sin x)(1+sinx+sin^2 x) =( cos^2 x+sin x)(1-sin x)
1+sinx+sin^2 x = cos^2 x + sin x
1=cos 2x
2x=0
x=0
Ответ
x= 2pi *n ; n прин z