Solve.
-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 10 m down from the top of the dome the ceiling is 16 m wide, find the best location for
The light source.
A) 1.6 m down from the top
B) 3.2 m down from the top
C) 6.4 m down from the top
D) 4.8 m down from the top

Question

Quizplus · Accepted Answer

The focus of a parabola is located halfway between the vertex and the directrix. The vertex is the top of the dome, and the directrix is a horizontal line 10 m below the vertex. Therefore, the focus is located 5 m below the vertex, or 1.6 m down from the top.

Solve. -A Domed Ceiling Is a Parabolic Surface. for the Best