2sin^3x+2cosx*sin^2x-sinx*cos^2x-cos^3x=0

Решите задачу:

$2\sin^3x+2\cos x\sin^2x-\sin x\cos^2x-\cos^3x=0\\ 2\sin^2 x(\sin x+\cos x)-\cos^2x(\sin x+\cos x)=0\\ (\sin x+\cos x)(2\sin^2x-\cos^2x)=0\\ \sin x+\cos x=0|:\cos x\\ tgx=-1 \\x=- \frac{\pi}{4}+ \pi n,n \in Z\\ \\ 2\sin^2x-\cos^2x=0| :\cos^2x\\ 2tg^2x-1=0\\ tgx=\pm \frac{1}{ \sqrt{2} } \\ x=arctg(\pm\frac{1}{ \sqrt{2} })+ \pi n,n \in Z$