Q. The length of the latusrectum of the parabola $x^{2} - 4x - 8y + 12 = 0$ is
A) 4
B) 6
C) 8
D) 10
Explanation
(c)
The given equation of parabola is
$x^{2} - 4x - 8y + 12 = 0$
$\Rightarrow x^{2} - 4x = 8y - 12$
$\Rightarrow x^{2} - 4x + 4 = 8y - 12 + 4$
$\Rightarrow {(x - 2)}^{2} = 8(y - 1)$
$\therefore$ The length of latusrectum $= 4a = 8$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.