\begin{tabular}{|l|l|}
\hline Q.33 & $\begin{array}{l}\text { The value of } k \text { that makes the complex-valued function } \\
\text { analytic, where } z=x+i y, \text { is } \\
\text { (Answer in integer })\end{array}$ \\
\hline$f(z)=e^{-k x}(\cos 2 y-i \sin 2 y)$ \\
\hline
\end{tabular}