I think that the vertex is (0,0) and the focus is (0,25) but thats about all. Please include any formulas that should be used. I'm not sure how to approach this problem.
-A reflecting telescope has a mirror shaped like a paraboloid of revolution. If the distance of the vertex to the focus is 25 feet and the distance across the top of the mirror is 66 inches, how deep is the mirror in the center?