Q.
The focal distance of a point $P$ on the parabola $y^{2} = 12x,$ if the ordinate of $P$ is 6, is
A) 12
B) 6
C) 3
D) 9
Explanation
(b)
Given parabola is $y^{2} = 12\ x$
Here, $a = \ \ 3$
For point $P(x,y),\ y = 6\$
This point lie on the parabola
$\therefore\ \ \ (6)^{2} = 12x\ \Rightarrow x = 3$
Thus , focal distance of point $P$ is 6
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.