How it works ?
Well, imagine spinning this parabola 360 degrees about its axis (of symmetry).
Doing so yields a 3D solid called a circular paraboloid of revolution.
Interact with this applet for a few minutes.
Be sure to slide the Slide Me! slider completely once before messing around with the other sliders!
Note: Point P is a point that lies on this solid. Move it wherever you’d like.