>

> with(plots):

Warning, the name changecoords has been redefined

> g:=(x,y)->x^3-3*x+y^3-3*y;

> plot3d(g(x,y),x=-2..2,y=-2..2,axes=boxed);

> contourplot(g(x,y),x=-2..2,y=-2..2,contours=10,filled=true);

>