Locus Question:
Tangents are drawn to a parabola x^2=4y from an external point A(x1, y1) touching the parabola at P and Q
Prove that the mid point M, of PQ is the point (x1, 1/2x1^2 - y1)
2 Questions that are destroying me:
12. PQ is a focal chord of the parabola x^2=4ay. Perpendiculars PA, QB are drawn from P, Q to meet the directrix at A, B repsectively.
Prove that PB, QA intersect at the vertext O