\documentclass{minimal}
\usepackage{pstricks}
\usepackage{pst-plot}
\pagestyle{empty}
\begin{document}

\begin{pspicture}(-5,-5)(5,5)
\psplot[plotpoints=1000,linecolor=blue,linewidth=1.5pt]{-5}{5}{x dup RadtoDeg 16 mul 3.14 div cos mul} 
\psline[linecolor=red](-5,-5)(5,5)
\psline[linecolor=red](-5,5)(5,-5)
\psaxes{->}(0,0)(-5,-5)(5,5)
\uput[-90](5,0){$x$}
\uput[0](0,5){$y$}
\end{pspicture}

\clearpage
\psset{yunit=0.5}
\begin{pspicture}(-5,10)(5,10)
\psplot[plotpoints=1000,linecolor=blue,linewidth=1.5pt]{-5}{5}{x dup RadtoDeg 16 mul 3.14 div cos mul x add} 
\psline[linecolor=red](-5,-10)(5,10)
\psaxes[Dy=2]{->}(0,0)(-5,-10)(5,10)
\uput[-90](5,0){$x$}
\uput[0](0,5){$y$}
\end{pspicture}

\end{document}
