definiera en funktion
> f:=(x,y)->sin((x-0.2)^2+x*y)+1.5;

                                         2
              f := (x, y) -> sin((x - .2)  + x y) + 1.5

> with(plots):
Rita funktionsgraf, enhetscirkeln i xy-planet och restriktionen av f till enhetcirkeln
> A:=plot3d(f(x,y),x=-1.3..1.3,y=-1.3..1.3,color=red):
> B:=spacecurve([cos(t),sin(t),0],t=0..2*Pi,color=blue,thickness=4):
> 
> C:=spacecurve([cos(t),sin(t),f(cos(t),sin(t))],t=0..2*Pi,color=black,thickness=4):
> display([A,B,C],style=wireframe,orientation=[-59,63],scaling=constrained);
>