câu 9 nhee

$\displaystyle \begin{array}{{>{\displaystyle}l}} \sin x.\left( 2\cos x-\sqrt{3}\right) =0\\ \Rightarrow \left[ \begin{array}{l l} \sin x=0 & \\ 2\cos x-\sqrt{3} =0 & \end{array} \right.\\ \Rightarrow \left[ \begin{array}{l l} \sin x=0 & \\ \cos x=\frac{\sqrt{3}}{2} & \end{array} \right.\\ \Rightarrow \left[ \begin{array}{l l} x=k\pi & \\ x=\pm \frac{\pi }{6} +k2\pi & \end{array} \right. k\in Z\\ A \end{array}$