Here, equation of tangent on C1 at (2,1) is: 2x+y−(x+2)−1=0 Or x+y=3 If it cuts off the chord of the circle C2 then the equation of the chord is: x+y=3 ∴ distance of the chord from (3,-2) is : d=|
3−2−3
√2
|=√2 Also, length of the chord is l=4 ∴ radius of C2=r=√(