giải phương trình sin2x -sin2xcosx =o <3

$\sin2x-\sin2x.\cos x=0$

$\to \sin2x(1-\cos x)=0$

$\to \left[ \begin{array}{l}\sin2x=0\\\cos x=1\end{array} \right.$

$\to \left[ \begin{array}{l}x=\dfrac{k\pi}{2}\\x=k2\pi\end{array} \right.$

$\to x=\dfrac{k\pi}{2}$