Circle And System Of Circles Question 195
Question: The circle $ x^{2}+y^{2}-8x+4y+4=0 $ touches
[Karnataka CET 1999, 2004; Pb. CET 2000]
Options:
A) x-axis only
B) y- axis only
C) Both x and y- axis
D) Does not touch any axis
Show Answer
Answer:
Correct Answer: B
Solution:
The given equation can be written as $ {{(x-4)}^{2}}+{{(y+2)}^{2}}=4^{2} $ .
We know that the standard equation of the circle with centre (h, k) is $ {{(x-h)}^{2}}+{{(y-k)}^{2}}=r^{2}. $
Comparing the given equation with the standard equation, we get centre º $ (4,,-2) $ and radius = 4.
Since co-ordinates of the centre of the circle are $ (4,,-2) $ , therefore the given circle touches y-axis only.
BETA
