> with(plots):

> plotsetup(inline):

> f:=(x,y)->cos(x*y);plot3d(f,-3..3,-3..3,grid=[50,50], axes=frame,scaling=constrained,style=patchnogrid,shading=zhue,orientation=[60,45]);

> f:=(x,y) -> x^2+y^2; plot3d(f,-3..3,-3..3,grid=[50,50], axes=frame,style=patchnogrid, shading=zhue, orientation=[60,45]);

> f:=(x,y)->x*y/(x^2+y^2);plot3d(f,-5..5,-5..5,grid=[50,50], axes=frame,orientation=[-15,30],style=patchnogrid, shading=zhue);

> f:=(x-y)^(-2);plot3d(f,x=-5..5,y=-5..5,grid=[25,25], axes=frame, style=wireframe,orientation=[50,60]);

> f:=x*y*(x^2+y^2)^(-1/2);plot3d(f,x=-5..5,y=-5..5,grid=[50,50], axes=frame,orientation=[-30,30],style=patchnogrid, shading=zhue);