Circle And System Of Circles Question 335
Question: Length of the tangent drawn from any point on the circle $ x^{2}+y^{2}+2gx+2fy+c_1=0 $ to the circle $ x^{2}+y^{2}+2gx+2fy+c=0 $ is
[Kerala (Engg.) 2002]
Options:
A) $ \sqrt{c_1-c} $
B) $ \sqrt{c-c_1} $
C) $ \sqrt{c_1+c} $
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
Suppose $ (x_1,\ y_1) $ be any point on first circle from which tangent is to be drawn, then $ x_1^{2}+y_1^{2}+2gx_1+2fy_1+c_1=0 $ …………. (i) and also length of tangent $ =\sqrt{S_2}=\sqrt{x_1^{2}+y_1^{2}+2gx_1+2fy_1+c} $ …………. (ii) From (i), we get (ii) as $ \sqrt{c-c_1} $ .
BETA
