Circle And System Of Circles Question 212
Question: The equation of the circle concentric with the circle $ x^{2}+y^{2}-4x-6y-3=0 $ and touching y-axis, is
Options:
A) $ x^{2}+y^{2}-4x-6y-9=0 $
B) $ x^{2}+y^{2}-4x-6y+9=0 $
C) $ x^{2}+y^{2}-4x-6y+3=0 $
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
Equation of circle concentric to given circle is $ x^{2}+y^{2}-4x-6y+k=0 $ It touches $ x=0 $ , therefore Radius = Perpendicular distance from centre to $ x=0 $
$ \Rightarrow \sqrt{4+9-k}=\frac{2}{\sqrt{1}}\Rightarrow k=9 $
Hence required equation is $ x^{2}+y^{2}-4x-6y+9=0 $ .
BETA
