Hàm số \(y = \tan \left( {\frac{x}{3} + \frac{\pi...

A

- Hướng dẫn giải

\(\begin{array}{l}
y = \tan \left( {\frac{x}{3} + \frac{\pi }{6}} \right) = \frac{{\sin \left( {\frac{x}{3} + \frac{\pi }{6}} \right)}}{{{\rm{cos}}\left( {\frac{x}{3} + \frac{\pi }{6}} \right)}}\\
 \Leftrightarrow {\rm{cos}}\left( {\frac{x}{3} + \frac{\pi }{6}} \right) \ne 0 \Leftrightarrow {\rm{cos}}\left( {\frac{x}{3} + \frac{\pi }{6}} \right) \ne c{\rm{os}}\frac{\pi }{2}\\
 \Leftrightarrow \frac{x}{3} + \frac{\pi }{6} \ne \frac{\pi }{2} + k\pi  \Leftrightarrow x \ne \pi  + k3\pi \left( {k \in Z} \right)
\end{array}\)