Find the centre of the circle `x^2 + y^2+ x - 4y - 4 = 0`.

Find the equation of the circle passing through the points of intersection of the circles x^2 + y^2 - 2x - 4y - 4 = 0 and x^2 + y^2 - 10x - 12y +40 = 0 and whose radius is 4.

The centre of the circle (x-1)^2+y^2=4 is

Write the co-ordinates of the centre of the circle : 2x^2 + 2y^2-6x+8y-4=0 .

Find the centre and radius of the circle : x^2 + y^2- 4x- 8y- 45 = 0 .

The centre of the circle x^(2)+y^(2)-6x+4y-1=0 is

Find the equation of the circle passing through the point of intersection of the circles x^2 + y^2 - 6x + 2y + 4 = 0, x^2 + y^2 + 2x - 4y -6 = 0 and with its centre on the line y = x.

Find the parametric representation of the circle x^2 + y^2 - 2x + 4y -4=0 .

Find the equation of the circle through points of intersection of the circle x^2 + y^2 -2x - 4y + 4 =0 and the line x + 2y = 4 which touches the line x + 2y = 0 .

Find the centre and radius of the circle : x^2 + y^2+ 8x + 10y- 8 =0 .

Find the centre and radius of the circle : x^2 + y^2- 8x+ 10y- 12 = 0 .