$$\cot ^ { 2 } x - ( \sqrt { 3 } + 1 ) \cot x + \sqrt { 3 } = 0$$
$x=\pi n_{1}+\frac{\pi }{4}\text{, }n_{1}\in \mathrm{Z}$
$x=\pi n_{1}+\frac{\pi }{6}\text{, }n_{1}\in \mathrm{Z}$
