question_answer

If a double ordinate of the parabola \[{{y}^{2}}=4ax\] be of length \[8a\], then the angle between the lines joining the vertex of the parabola to the ends of this double ordinate is

A)            30o 

B)            60o

C)            90o 

D)            120o

Correct Answer: C

Solution :

           It is clear from figure.