Question

If incident ray from point $(-1,2)$ parallel to the axis of the parabola $y^2=4x$ strikes the parabola than find the equation of reflected ray ?

Answer 1

Axis of parabola: $y=0$
Therefore, equation of incident ray: $y=2$
Point of intersection of parabola and ray: $(1,2)$
Property: Ray parallel to axis of parabola passes through focus on reflection.
(If the ray is incident from outside the parabola, it passes through the focus upon extension.)
Focus of parabola: $(1,0)$
Therefore, equation of reflected ray: Equation of line joining $(1,2)$ and $(1,0)$.
Required equation: $x=1$