A. √4c2-2(a-b)2

B. √4c2-(a-b)2

C. √2c2-2(a-b)2

D. √c2-(a-b)2

The external centre of similitude of the two circles x^{2}+y^{2}-2x-6y+9=0, x^{2}+y^{2}=4 is

The longest distance from (-3, 2) to the circles x^{2}+y^{2}-2x+2y+1=0 is

If the equation of the circle passing through the origin and the points of intersection of the two circles x^{2}+y^{2}-4x-6y-3=0, x^{2}+y^{2}+4x-2y-4=0 is x^{2}+y^{2}+2ax+2by+c=0 then the ascending order of a, b,c is

The circle passing through the points (1, t), (t, 1) and (t, t) for all values of t passes through the point

The equation of the circle passing through the points of intersection of the circles x^{2}+y^{2}+2x+3y+1=0, x^{2}+y^{2}+4x+3y+2=0 and through the point (-1, 2)is