y=x+2 is any tangent to the parabola y2=8x . The ordinate  of the point P on this tangent such that the other tangent  from it which is perpendicular to it is

Clearly P is the point of intersection of two perpendicular  tangents to the parabola y2=8x .  Here, 4a=8 or a=2 Hence P must lie on the directrix x+a=0 or x+2=0∴x=−2 . Hence the point is (−2,0) .