Question
Question: A ray of light travels along a line y = 4 and strikes the surface of a curve y<sup>2</sup> = 4(x + y...
A ray of light travels along a line y = 4 and strikes the surface of a curve y2 = 4(x + y) then equation of the line along reflected ray travel is
A
x = 0
B
x = 2
C
x + y = 4
D
2x + y = 4
Answer
x = 0
Explanation
Solution
Given curve is (y – 2)2 = 4(x + 1)
focus (x + 1 = 1, y – 2 = 0) Ž (0, 2)
Point of intersection of the curve and y = 4
is (0, 4) from the reflection property of parabola reflected ray passes through the focus.
\ x = 0 is required line