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. `sqrt(3)`
B. `sqrt(2)`
C. 3
D. 2

Answer 1

Correct Answer - C
Let PQ be a diameter of the circle `x^(2)+y^(2)-2x-6y+6=0` such that PQ is a chord of the circle having its centre at C(2, 1). Clearly,
Radius `= CP=sqrt(BC^(2)+BP^(2))=sqrt((2-1)^(2)+(1-3)^(2)+2^(2))=3`