Prove that the centres of the circles `x^2+y^2=1`, `x^2+y^2+6x-2y-1=0` and `x^2+y^2-12x+4y=1` are collinear

Find the centre of the circle 3x^2+3y^2-6x-12y-2=0

Prove that the radii of the circles x^(2)+y^(2)=1,x^(2)+y^(2)-2x-6y=6andx^(2)+y^(2)-4x-12y=9 are in AP.

Co-ordinates of radical centre of the circles : x^2+y^2 = 9 , x^2+y^2 -2x -2y =5 and x^2+y^2 +4x + 6y =19 are :

The circles x^2+y^2-12x-12y=0 and x^2+y^2+6x+6y=0 :

Circles x^2+y^2-2x-4y=0 and x^2+y^2-8y-4=0

Find the centre and radius of the circle x^2+y^2-10x+4y+1=0

The radical axis of the circles x^(2)+y^(2)+2x+2y+1=0 and x^(2)+y^(2)-10x-6y+14=0 is

The angles between the circle x^2 + y^2 -2x - 6y - 39=0 and x^2 + y^2 + 10x - 4y + 20=0 is

One of the diameters of the circle x^(2)+y^(2)-12 x+4 y+6=0 is given by

Length of the common chord of the circles : x^2+y^2+2x+6y=0 and x^2+y^2-4x-2y-6=0 is :