A Domed Ceiling Is a Parabolic Surface

Multiple Choice

A domed ceiling is a parabolic surface. For the best lighting on the floor, a light source is to be placed at the focus of the surface. If 2 m down from the top of the dome the ceiling is 28 m wide, find the best location for the
Light source.

A) 49 m down from the top
B) 73.5 m down from the top
C) 98 m down from the top
D) 24.5 m down from the top