Question

A parabolic microphone used on the sidelines of a professional football game uses a reflective dish 24 inches wide and 6 inches deep. How far from the bottom of the disk should the microphone be placed?
a.) 6 in
b.) 5.8 in
c.) 5.2 in
d.) 4 in

Answer 1

The answer is a.
When you are solving problems like this you would use the equation y^2=4ax. The x and Y would be the coordinates. Based on the equation you have given the coordinates would be (6,12) and (6,-12), (24 is split up evenly between the y-axis).  
Then we go on to solve the equation by plugging in the numbers 12^2=4a(6)
144=24a
144/24=24a/24
6=a