Circle And System Of Circles Question 205
Question: The co-ordinates of pole of line $ lx+my+n=0 $ with respect to circles $ x^{2}+y^{2}=1 $ , is
[RPET 1987]
Options:
A) $ ( \frac{l}{n},\frac{m}{n} ) $
B) $ ( -\frac{l}{n},-\frac{m}{n} ) $
C) $ ( \frac{l}{n},-\frac{m}{n} ) $
D) $ ( -\frac{l}{n},\frac{m}{n} ) $
Show Answer
Answer:
Correct Answer: B
Solution:
Let pole be $ (x_1,y_1) $ then polar will be $ xx_1+yy_1=1 $ comparing with $ lx+my+n=0 $
$ \Rightarrow x_1=-\frac{l}{n},\ y_1=-\frac{m}{n} $ .
BETA
