a lamp with a parabolic reflector is shown in the figure. the bulb is placed at the focus and the focal diameter is 12cm. (assume the vertex O is at the origin. let the x-axis be horizontal and the y-axis be vertical.) a) find an equation of thr parabola. b) find the diameter d(C,D) of the opening, 24cm from the vertex(round your answer to the nearest whole number)

A lamp with a parabolic reflector is shown in the figure. The bulb is placed at the focus and the focal diameter is 12 cm. (Assume the vertex O is at the origin. Let the x-axis be horizontal and the y-axis be vertical.) O 6 cm 24 cm 6 cm D (a) Find an equation of the parabola. ( Round your answer to the nearest whole number.) by Find the diameter d(C, D) of the opening