Conic Sections Question 144

Question: If the normals at two points P and Q of a parabola $ y^{2}=4ax $ intersect at a third point R on the curve, then the product of ordinates of P and Q is

Options:

A) $ 4a^{2} $

B) $ 2a^{2} $

C) $ -4a^{2} $

D) $ 8a^{2} $

Show Answer

Answer:

Correct Answer: D

Solution:

As we know, $ t_1\times t_2=2 $

therefore $ 2at_1\times 2at_2=8a^{2} $ .