Q. Number of points from where perpendicular tangents to the curve $\frac{x^{2}}{16} - \frac{y^{2}}{25} = 1$ can be drawn, is
A) 1
B) 2
C) 0
D) None of these
Explanation
(c)
Director circle is set of points from where drawn tangents are perpendicular, in this case $x^{2} + y^{2} = a^{2} - b^{2}$ (equation of director circle) $ie,\ x^{2} + y^{2} = - 9$ is not a real circle, so there is no point from where tangents are perpendicular.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.