\documentclass[pst2pdf]{webquiz} \usepackage{pst-all,pst-3dplot} \title{A pst2pdf example} \begin{document} \begin{question} % a quiz question Which of the equations below could describe the following surface? \begin{pspicture*}(-4,-4)(4,4) \psplotThreeD[linecolor=blue, plotstyle=curve, drawStyle=yLines, yPlotpoints=30, xPlotpoints=30, linewidth=1pt](-4,1)(-4,1){ x dup mul y dup mul add 1.01 exp} \pstThreeDCoor[linewidth=1pt, xMin=-4,xMax=4,yMin=-4,yMax=4,zMin=-2,zMax=6] \end{pspicture*} \begin{choice} \incorrect \( z=\log(x^2+y^2) \) \correct \( z=e^{x^2+y^2} \) \incorrect \( z=1-e^{x^2+y^2} \) \incorrect \( z=\dfrac1{x^2+y^2}\) \end{choice} \end{question} \end{document}