\documentclass{article}
\RequirePackage{pstricks}
\RequirePackage{pstricks-add}
\pagestyle{empty}
\parindent=0pt

\begin{document}

\begin{pspicture}(-5,-5)(5,5)
\psset{linewidth=1mm,polarplot=true,plotpoints=5000}%
\psplot[linecolor=PineGreen,fillstyle=solid,fillcolor=BlueGreen]{0}{360}{%
  x 2 mul cos 2 mul abs 9 mul sqrt}
\psaxes[labelsep=.75mm,arrowlength=1.75,ticksize=2pt,linewidth=0.17mm]%
  {->}(0,0)(-5,-5)(5,5)%
\uput[-90](5,0){$x$}
\rput[0](0,5){$y$}
\end{pspicture}

\end{document}
