Question

If one of the diameters of the circle `x^2+y^2-2x-6y+ 6 = 0` is a chord to the circle with centre (2, 1), then the radius of circle is:
A. `sqrt3`
B. `sqrt2
C. 3
D. 2

Answer 1

Correct Answer - C
Here, radius of smaller circle, AC`=sqrt(1^(2)+3^(2)-6)=2` Clearly, from the figure the radius of bigger circle
`r^(2)=2^(2)+[(2-1)^(2)+(1-3)^(2)]`
`r^(2)=9 rArr r = 3`