Question
Question: C<sub>1</sub> is a circle of radius 2 touching the x-axis and the y-axis. C<sub>2</sub> is another c...
C1 is a circle of radius 2 touching the x-axis and the y-axis. C2 is another circle of radius > 2 and touching the axes as well as the circle C1. Then the radius of C2 is-
A
6 – 42
B
6 + 42
C
6 –43
D
6 +43
Answer
6 + 42
Explanation
Solution
C1 (2, 2) r1 = 2
C2 (r, r) r2 = r
and C1C2 = r1 + r2
(r –2)2 + (r –2)2 = (2 + r)2
r2 – 12r + 4 = 0
r = 6 ±42
6 –42< 2 then r = 6 +42