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)
Responses

4 inches
4 inches

18 inches
18 inches

9 inches
9 inches

12 inches