\[\begin{array}{l}
\tan x = - \sqrt 3 - 2\,\,\,\left( {\cos x \ne 0} \right)\\
\Leftrightarrow \tan x = \tan \left( { - \frac{{5\pi }}{{12}}} \right)\\
\Leftrightarrow x = - \frac{{5\pi }}{{12}} + k\pi \,\,\left( {k \in Z} \right)\\
\tan x = - \sqrt 3 + 2\,\,\,\left( {\cos x \ne 0} \right)\\
\Leftrightarrow \tan x = \tan \frac{\pi }{{12}}\\
\Leftrightarrow x = \frac{\pi }{{12}} + k\pi \,\,\left( {k \in Z} \right)
\end{array}\]
