12-12

> restart;

> x:=r*cos(t)/sqrt(2):;

> y:=r*sin(t):

> z1:=5*x^2+5*y^2:

> a:=plot3d([x,y,z1],r=0..1,t=0..2*Pi,scaling=constrained):

> a;

> z2:=6-7*x^2-y^2:

> b:=plot3d([x,y,z2],r=0..1,t=0..2*Pi,scaling=constrained,grid=[10,50]):

> b;

> with(plots):

Warning, the name changecoords has been redefined

> p:=display(a,b):p;

> with(plottools):

> vrml(p,"c:/program files/maple 6/beauty/12-12.wrl",background_color=white);

>