A ray of light passing through the point A and the reflected ray passes through the point (1,2) reflects on the x-axis at point A and the reflected ray passes through the point (5,3). Find the coordinates of A.
Let BA be the incident ray and AC be the reflected ray.
Now for line AC
tan ϕ=3−05−x
⇒ tan ϕ=35−x …(i)
Now for line BA
tan (180−ϕ)=2−01−x
⇒ −tan ϕ=21−x …(ii)
From (i) and (ii) we have
35−x=−21−x
⇒ 3−3x=−10+2x
⇒ −5x=−13⇒x=135
Thus coordinates of point A are (135,0).