%typeset_mode True
f(x,y) = e^x * cos(y)
P3(x,y) = f.taylor((x,0),(y,0),3) P3(x,y)
Surff = plot3d(f(x,y),(x,-1,1),(y,-pi,pi), color="blue", opacity = 0.5) SurfP3 = plot3d(P3(x,y),(x,-1,1),(y,-pi,pi), color="red", opacity = 0.5) show(Surff+ SurfP3, frame_aspect_ratio = [2,2,1])