P (2ap,ap ²) and Q(2aq, aq ²) are points on x ²=4ay, and the chord PQ subtends a right angle at the vertex O.

Question

A)show that pq=-4. This question is related to the locus however i do not know how to answer the question. Could you show the step by step process.

Answer 1

HINT...the gradient of OP is $\frac{ap^2}{2ap}$ and similarly for OQ. then use $m_1.m_2=-1$ for perpendicular gradients