> with(plots);

Warning, the name changecoords has been redefined

> implicitplot3d(x^2+y^2-z^2=1,x=-3..3,y=-3..3,z=-3..3);

> implicitplot3d(x^2-y^2-z^2=1,x=-3..3,y=-3..3,z=-3..3);

>