Given, y2=16x a=4 Let B be (x1,12) lies on parabola. ‌ (12) ‌‌2=16x1⇒x1=‌
12×12
16
=9 Point B(9,12) Equation of focal chord passing through (4,0) and (2,2) y−0=‌
2−0
2−4
(x−4) y=−x+4 x+y=4‌‌‌⋅⋅⋅⋅⋅⋅⋅(i) Equation of double ordinate : x=9‌‌‌⋅⋅⋅⋅⋅⋅⋅(ii) Point of intersection of Eqs. (i) and (ii), (9,−5).