Question

A ray of light moving parallel to the x-axis gets reflected from a parabolic mirror whose equation is $( y - 2 ) ^ { 2 } = 4 ( x + 1 )$ After reflection, the ray must pass through the point

• A. (0, 2)
• B. (2, 0)
• C. (0, –2)
• D. (–1, 2)

Answer 1

Answer: (A)

(0, 2)

Answer 2

The equation of the axis of the parabola is $y - 2 = 0$ , which is parallel to the x-axis. So, a ray parallel to x-axis is parallel to the axis of the parabola. We know that any ray parallel to the axis of a parabola passes through the focus after reflection. Here (0, 2) is the focus