Q. The equation of the parabola with vertex $( - 1,1)$ and focus $(2,1)$ is
A) $y^{2} - 2y - 12x - 11 = 0$
B) $x^{2} + 2x - 12y + 13 = 0$
C) $y^{2} - 2y + 12x + 11 = 0$
D) $y^{2} - 2y - 12x + 13 = 0$
Explanation
(a)
By the condition of parabola
$PM^{2} = PS^{2}$
$\Rightarrow \ \ (x + 4)^{2} = (x - 2)^{2} + (y - 1)^{2}$
[image:11_image86.emf]
$\Rightarrow \ y^{2} - 2y - 12x - 11 = 0$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.