Let us now take a look at an ellipsoid defined by the following implicit equation. 

Use the implicitplot3d(...) command to plot this type of equation. 

That doesn't look much like an ellipsoid. The reason is that the default number of points (625) plotted is too small. Try a larger one. 

Much better. But notice it took longer as there are substantially more calculations involved. 

Let's look at the other surfaces 

Here we can create an Elliptic Paraboloid two ways. The first sets an expression in z 

Or we can implicitly define the Elliptic Paraboloid as we did the other surfaces 

(But first we need to clear z) 

Finally we do the Hyperbolic Paraboloid in the same fashion