Circle And System Of Circles Question 27
Question: If $ 2x-4y=9 $ and $ 6x-12y+7=0 $ are the tangents of same circle, then its radius will be
[Roorkee 1995]
Options:
A) $ \frac{\sqrt{3}}{5} $
B) $ \frac{17}{6\sqrt{5}} $
C) $ \frac{2\sqrt{5}}{3} $
D) $ \frac{17}{3\sqrt{5}} $
Show Answer
Answer:
Correct Answer: B
Solution:
Since the tangents are parallel, therefore the distance between these two tangents will be its diameter i.e., diameter $ =\frac{34}{\sqrt{180}}=\frac{17}{3\sqrt{5}} $
Hence, radius $ =\frac{17}{6\sqrt{5}} $ .
BETA
