The reflecting dish of a parabolic microphone has a cross-section in the shape of a parabola. The microphone itself is placed on the focus of the parabola. If the parabola is 24 inches wide and 4 inches deep, how far from the vertex should the microphone be placed?
(1 point)
4 inches
18 inches
9 inches
12 inches
9 inches
This can be calculated using the formula for the distance from the vertex to the focus of a parabola, which is equal to a^2 / 4c, where a is the width of the parabola and c is the depth.
In this case, a = 24 inches and c = 4 inches. Plugging in these values:
9 = 24^2 / (4*4)
9 = 576 / 16
9 = 36
Therefore, the microphone should be placed 9 inches from the vertex.