\documentclass[10pt,x11names, pdf]{standalone}\usepackage{pstricks-add}%\usepackage{pst-func, pst-plot}\begin{document}\psset{algebraic=true,dimen=middle,dotstyle=o,linewidth=0.8pt,arrowsize=3pt 2,arrowinset=0.25,unit=3,plotpoints = 2000}\begin{pspicture*}(-2,-2)(2,2) \psset{linecolor =SteelBlue4, linewidth = 1.2pt} \pscustom[fillstyle = solid, fillcolor =lightgray!25!LightSteelBlue2!10!]{ \parametricplot{-0.99}{0}{3*t/(1 + t^3) | 3*t^2/(1 + t^3)} \parametricplot{-600}{-1.01}{3*t/(1 + t^3) | 3*t^2/(1 + t^3)} }\pscustom[fillstyle = solid, fillcolor =LightSteelBlue2!25! ]{ \parametricplot{0}{5}{3*t/(1 + t^3) | 3*t^2/(1 + t^3)} \parametricplot{5}{200}{3*t/(1 + t^3) | 3*t^2/(1 + t^3)} \closepath } %\psline[linewidth = 0.4pt, linecolor = black](-2.5; 45)(2.5 ; 45) \psline[linewidth = 0.4pt, linecolor = black](-2,1)(2,-3)\psaxes[linecolor=gray,xAxis=true,yAxis=true,labels=none,ticks=none]{->}(0,0)(-2,-2)(2,2)\rput(-0.1,-0.1){$O$}\rput(1.95,-0.1){$x$}\rput(-0.1,1.95){$y$}\rput(-0.5,-0.08){$a$}\rput(-0.08,-0.5){$a$}\end{pspicture*}\end{document}