2 câu trả lời
#andy
\[\begin{array}{l}
{\sin ^2} + {\cos ^2}a = 1\\
\Rightarrow \cos a = \frac{{2\sqrt 6 }}{5}\\
\tan a = \frac{{\sin a}}{{\cos a}} = \frac{{\sqrt 6 }}{{12}}\\
\cot a = \frac{{\cos a}}{{\sin a}} = 2\sqrt 6
\end{array}\]
#andy
\[\begin{array}{l}
{\sin ^2} + {\cos ^2}a = 1\\
\Rightarrow \cos a = \frac{{2\sqrt 6 }}{5}\\
\tan a = \frac{{\sin a}}{{\cos a}} = \frac{{\sqrt 6 }}{{12}}\\
\cot a = \frac{{\cos a}}{{\sin a}} = 2\sqrt 6
\end{array}\]