Let P = (h, k) be the point of intersection of tangents at A & B ∴ equation of chord of contact AB is xha2+ykb2=1 Which touches the paraboia equation of tangent to parabola y2=4axy=mx+am⇒mx−y=−am. Equation (i) & (ii) as must be same
∴m(ha2)=−1(kb2)=−am1⇒m=−hkb2a2 & m=akb2∴−hb2ka2=akb2⇒ locus of P is y2=−b4a3.x