Circle And System Of Circles Question 23
Question: The line $ lx+my+n=0 $ is normal to the circle $ x^{2}+y^{2}+2gx+2fy+c=0 $ , if
[MP PET 1995]
Options:
A) $ lg+mf-n=0 $
B) $ lg+mf+n=0 $
C) $ lg=mf-n=0 $
D) $ lg-mf+n=0 $
Show Answer
Answer:
Correct Answer: A
Solution:
Since normal always passes through centre of circle, therefore $ (-g,\ -f) $ must lie on $ lx+my+n=0 $ .
Hence $ lg+mf-n=0 $ .
BETA
