Circle And System Of Circles Question 1
Question: The common chord of the circle $ x^{2}+y^{2}+4x+1=0 $ and $ x^{2}+y^{2}+6x+2y+3=0 $ is
[MP PET 1991]
Options:
A) $ x+y+1=0 $
B) $ 5x+y+2=0 $
C) $ 2x+2y+5=0 $
D) $ 3x+y+3=0 $
Show Answer
Answer:
Correct Answer: A
Solution:
$ S_1=x^{2}+y^{2}+4x+1=0 $
$ S_2=x^{2}+y^{2}+6x+2y+3=0 $
Common chord $ \equiv S_1-S_2=0\Rightarrow 2x+2y+2=0 $
$ \Rightarrow x+y+1=0 $ .
BETA
