The reflective surface is given by `y=2 sinx`. The reflective surface is facing positive axis. What is the least value of coordinate of the point where a ray parallel to positive `x`-axis becomes parallel to positive `y` -axis after reflection?

Options

A. `((pi)/3,sqrt(3))`
B. `((pi)/2,sqrt(2))`
C. `((pi)/3,sqrt(2))`
D. `((pi)/4,sqrt(3))`

Explanation

(a) Let the incidence point is
`P(x,y)`
`m=tan45^(@)=1`
(from law of reflection)
`y=2 sin x`
`:.m=(dy)/(dx)=2 cos x=1`
`cosx=1/2impliesx=(pi)/3`
The corresponding value of `y` is `2 "sin" (pi)/3=sqrt(3)`