The correct option (a) 3
Explanation:
Circle is x2 + y2 – 2x – 6y + 6 = 0
∴ Centre of circle is (1, 3)
Radius = √(1 + 9 – 6) = 2
Required equation of circle is
(x – 2)2 + (y – 1)2 = r2 .....(1)
Common chord of (1) and circle
x2 + y2 – 2x – 6y + 6 = 0 is – 2x + 4y + 5 – r2 – 6 = 0
given: it is diameter of circle (2)
∴ – 2(1) + 4(3) + 5 – r2 – 6 = 0
∴ r2 = 9
∴ r = 3
∴ Radius of required circle is 3.