Circle And System Of Circles Question 193
Question: The equation of circle whose centre lies on $ 3x-y-4=0 $ and $ x+3y+2=0 $ and has an area 154 square units is
[DCE 2001]
Options:
A) $ x^{2}+y^{2}-2x+2y-47=0 $
B) $ x^{2}+y^{2}-2x+2y+47=0 $
C) $ x^{2}+y^{2}+2x-2y-47=0 $
D) None of these
Show Answer
Answer:
Correct Answer: A
Solution:
Centre is $ (1,,-1) $ (point of intersection of two given lines) and $ \pi r^{2}=154\Rightarrow ,r=7 $
$ \therefore $ Equation of required circle is $ {{(x-1)}^{2}},+{{(y+1)}^{2}}=49 $
$ \Rightarrow , $ $ x^{2}+y^{2}-2x+2y-47=0. $
BETA
