12.10Construct the surface given by the equation z=4-sqrt(abs(x*y))

over the square [-2, 2] x [-2,2].

> restart;

> a:=plot3d(4-sqrt(abs(x*y)),x=-2..2,y=-2..2,scaling=constrained):;

> a;

> with(plottools):

> vrml(a,"c:/program files/maple 6/beauty/12-10-1.wrl",background_color=white);

Construct the same surface located above the disc (x^2+y^2)<=4

> restart;

> x:=r*cos(t);

> y:=r*sin(t):;

> z:=4-sqrt(abs(x*y));

> b:=plot3d([x,y,z],r=0..2,t=0..2*Pi,scaling=constrained,grid=[10,100]):b;

> with(plottools):

> vrml(b,"c:/program files/maple 6/beauty/12-10-2.wrl",background_color=white);

>