The radius of a circle with centre `(a, b)` and passing through the centre of the circle `x^2 + y^2 – 2gx + f^2 = 0` is -

Equation of the circle with centre at (1,-2) , and passing through the centre of the circle x^(2) + y^(2) + 2y - 3 = 0 , is

Find the equation of the circle with centre at (1,-2) and passing through the centre of the circle x^2+y^2-4x+1=0

Find the equation of the circle whose centre is (2, -4) and which passes through the centre of the circle x^(2) + y^(2) - 2x + 2y - 38 = 0 .

Find the equation of the circle whose centre is the point (1,-2) and which passes through the centre of the circle x^2 + y^2 + 2y = 3 .

Find the centre and radius of the circles : x^2 + y^2 - ax - by = 0

Find the centre and radius of the circles : x^2 + y^2 - ax - by = 0

Equation of the circle concentric with the circle x^(2) + y^(2) + 8x + 10 y - 7 = 0 , and passing through the centre of the circle x^(2) + y^(2) - 4x - 6y = 0 ,is

Equation of the circle concentric with the circle x^(2) + y^(2) + 8x + 10 y - 7 = 0 , and passing through the centre of the circle x^(2) + y^(2) - 4x - 6y = 0 ,is

The locus of the centre of the circle passing through the intersection of the circles x^2+y^2= 1 and x^2 + y^2-2x+y=0 is

The equation of the circle concentric with the circle x^2+y^2+8x+10y-7=0 and passing through the centre of the circle x^2+y^2-4x-6y=0 is