Automotive Automobile headlights contain parabolic reflectors, which work on the principle that light placed at the focus of a parabola will reflect off the mirror-like surface in lines parallel to the axis of symmetry. Suppose a bulb is placed at the focus of a headlight's reflector, which is 2 inches from the vertex.
a. If the depth of the headlight is to be 4 inches, what should the diameter of the headlight be at its opening?
b. Find the diameter of the headlight at its opening if the depth is increased by 25%
