Đáp án: D+C
Giải thích các bước giải:
$\begin{array}{l}
1)Dkxd:2\sin x - \sqrt 3 \# 0\\
\Leftrightarrow \sin x\# \dfrac{{\sqrt 3 }}{2}\\
\Leftrightarrow \sin x\# \sin \dfrac{\pi }{3}\\
\Leftrightarrow \left\{ \begin{array}{l}
x\# \dfrac{\pi }{3} + k2\pi \\
x\# \pi - \dfrac{\pi }{3} + k2\pi
\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}
x\# \dfrac{\pi }{3} + k2\pi \\
x\# \dfrac{{2\pi }}{3} + k2\pi
\end{array} \right.\\
\Leftrightarrow D\\
C2)\\
Do:y = \tan \left( {\dfrac{x}{2} - \dfrac{\pi }{4}} \right) = \dfrac{{\sin \left( {\dfrac{x}{2} - \dfrac{\pi }{4}} \right)}}{{\cos \left( {\dfrac{x}{2} - \dfrac{\pi }{4}} \right)}}\\
\Leftrightarrow DKxd:\cos \left( {\dfrac{x}{2} - \dfrac{\pi }{4}} \right)\# 0\\
\Leftrightarrow \left( {\dfrac{x}{2} - \dfrac{\pi }{4}} \right)\# \dfrac{\pi }{2} + k\pi \\
\Leftrightarrow x\# \dfrac{{3\pi }}{2} + k2\pi \\
\Leftrightarrow C
\end{array}$
