Mn giúp mk tìm nghiệm pt Căn 4-x bình nhân sin2x=0

$\begin{array}{l} \sqrt {4 - {x^2}} \sin 2x = 0\,\,\,\left( * \right)\\ DK:\,\,\,4 - {x^2} \ge 0 \Leftrightarrow - 2 \le x \le 2\\ \left( * \right) \Leftrightarrow \left[ \begin{array}{l} \sqrt {4 - {x^2}} = 0\\ \sin 2x = 0 \end{array} \right. \Leftrightarrow \left[ \begin{array}{l} {x^2} - 4 = 0\\ 2x = k\pi \,\,\, \end{array} \right.\\ \Leftrightarrow \left[ \begin{array}{l} x = \pm 2\\ x = \frac{{k\pi }}{2}\,\,\left( {k \in Z} \right) \end{array} \right.\\ - 2 \le x \le 2 \Rightarrow - 2 \le \frac{{k\pi }}{2} \le 2 \Leftrightarrow - 1,27 \le k \le 1,27\\ \Rightarrow k = 0 \Rightarrow x = 0\\ Vay\,\,pt\,\,co\,\,tap\,\,nghiem:\,\,\,S = \left\{ { - 2;\,\,0;\,\,2} \right\}. \end{array}$