.
Stein Glass, Inc., makes parabolic headlights for a variety of automobiles.
If one of its headlights has a parabolic surface generated by the parabola x^2 = 12y,
where should its light bulb be placed? (Hint: Solve the equation for y before you start finding the focus.)
A. 3 units
B. 12 units
C. 4 units
D. 48 units
E. 36 units
F. 2 units
~~~~~~~~~~~~~~~~~~~~~~
When a parabola is presented by an equation x^2 = ay in this vertex form,
the focus is located at the distance f = from the vertex.
In this problem, the focus is located at the distance = 3 units from the vertex.
ANSWER. Light buble should be placed at 3 units from the vertex.
Option (A).
Solved.