\begin{center}
\setlength{\unitlength}{0.75cm}%
\begin{Picture}[black!10!white](-4,-3)(4,3)
\renewcommand{\Pictlabelsep}{0.2}
\cartesianaxes(-3.5,-2.5)(3.5,2.5)
\Put[r](3.5,0){$x$}
\Put[t](0,2.5){$y$}
\end{Picture}
\end{center}
