<%=request("i")%>

surface: f(x,y,z)=0 or z=f(x,y)
1. cut in from x-axis, spin around x-axis. 2. cut in from y-axis, spin around y-axis.
3. cross section, cut off from x-axis, spin around x-axis. 4. cross section, cut off from y-axis, spin around y-axis.

" size=80% onChange=javascript:plot3d("section3D") title="section3D(x)">
open the graphic in a separate full window.