$y=x+2\text{ is any tangent to the parabola }{y}^2=8x\text{ . The ordinate of the point }P\text{ on this tangent such that the other tangent }$

$\text{ from it which is perpendicular to it is }$

$\text{ Clearly }P\text{ is the point of intersection of two perpendicular tangents to the parabola }{y}^2=8x\text{ . }$

$\text{ Here, }4a=8\text{ or }a=2\text{ Hence }P\text{ must lie on the directrix }$

$\begin{array}{l}x+a=0\text{ or }x+2=0\\ \therefore x=-2\text{ . Hence the point is }(-2,0)\text{ . }\end{array}$