Answer
\[undefined\]
Work Step by Step
\[\begin{gathered}
Using\,\,definition\,.\,\,of\,\,\tan \theta \hfill \\
\hfill \\
\tan \pi = \frac{{\cos \pi }}{{\sin \,\pi }} = \frac{{ - 1}}{0} \hfill \\
\hfill \\
{\text{Therefore}} \hfill \\
\hfill \\
\,we\,obtained\,zero\,in\,denominator\,,\,The\,expression\, \hfill \\
is\,undefined. \hfill \\
\end{gathered} \]
