Circle And System Of Circles Question 4
Question: Circles $ x^{2}+y^{2}-2x-4y=0 $ and $ x^{2}+y^{2}-8y-4=0 $
[IIT 1973]
Options:
A) Touch each other internally
B) Touch each other externally
C) Cuts each other at two points
D) None of these
Show Answer
Answer:
Correct Answer: A
Solution:
$ C_1(1,\ 2),\ C_2(0,\ 4),\ R_1=\sqrt{5},\ R_2=2\sqrt{5} $
$ C_1C_2=\sqrt{5} $ and $ C_1C_2=\ |R_2-R_1| $
Hence circles touch internally.
BETA
