Circle And System Of Circles Question 11
Question: The equation of the tangents to the circle $ x^{2}+y^{2}+4x-4y+4=0 $ which make equal intercepts on the positive coordinate axes is given by
Options:
A) $ x+y+2\sqrt{2}=0 $
B) $ x+y=2\sqrt{2} $
C) $ x+y=2 $
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
Equation of tangent is of the form $ x+y+c=0 $ and also it obeys condition of tangency,
i.e., $ | \frac{-2+2+c}{\sqrt{2}} |=\sqrt{4+4-4}\Rightarrow c=\pm ,2\sqrt{2} $
But for positive intercepts, $ c=-2\sqrt{2} $ \ The tangent is $ x+y=2\sqrt{2} $ .
BETA
