Q. The equation of the director circle of the hyperbola $\frac{x^{2}}{16} - \frac{y^{2}}{4} = 1$, is given by
A) $x^{2} + y^{2} = 16$
B) $x^{2} + y^{2} = 4$
C) $x^{2} + y^{2} = 20\$
D) $x^{2} + y^{2} = 12$
Explanation
(d)
Equation of director circle of the parabola
$\frac{x^{2}}{16} - \frac{y^{2}}{4} = 1\$
$x^{2} + y^{2} = 16 - 4\$
$\Rightarrow x^{2} + y^{2} = 12\$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.