Elliptic Paraboloids

This is the equation of an elliptic paraboloid whose axis is the z-axis.

Notice that the form is different from that of the above implicit equations.

It is an explicit equation, of the form "z=..."

> ellpara:=x^2/a^2+y^2/b^2;

Let's check it out for a=1, and b=2

> ellpara1:=subs({a=1,b=2},ellpara);

>

Plot of the elliptic paraboloid "ellpara1"