Conic Sections Question 220
Question: The radius of the director circle of the hyperbola $ \frac{x^{2}}{a^{2}}-\frac{y^{2}}{b^{2}}=1 $ , is
[MP PET 1999]
Options:
A) $ a-b $
B) $ \sqrt{a-b} $
C) $ \sqrt{a^{2}-b^{2}} $
D) $ \sqrt{a^{2}+b^{2}} $
Show Answer
Answer:
Correct Answer: C
Solution:
Equation of director-circle of the hyperbola $ \frac{x^{2}}{a^{2}}-\frac{y^{2}}{b^{2}}=1 $ is $ x^{2}+y^{2}=a^{2}-b^{2} $
So, radius $ =\sqrt{a^{2}-b^{2}} $ .
BETA
