Find the equation of the circle of minimum radius which contains the three circles
`x^2-y^2-4y-5=0`
`x^2+y^2+12x+4y+31=0` and
`x^2+y^2+6x+12y+36=0`

Find the equation of the circle which cuts the three circles x^2+y^2-3x-6y+14=0,x^2+y^2-x-4y+8=0, and x^2+y^2+2x-6y+9=0 orthogonally.

The equation of the circle whose diameter is the common chord of the circles x^2+y^2+3x+2y+1=0 and x^2+y^2+3x+4y+2=0 is

Find the equation of the circle whose radius is 5 and which touches the circle x^2+y^2-2x-4y-20=0 externally at the point (5,5) .

Find the equation of the circle described on the common chord of the circles x^2+y^2-4x-5=0 and x^2+y^2+8x+7=0 as diameter.

Find the equation to the circle described on the common chord of the circles x^(2) + y^(2) - 4x - 2y - 31 = 0 and 2x^(2) + 2y^(2) - 6x + 8y - 35 = 0 as diameter.

Find the equation to the common chord of the two circles x^(2) + y^(2) - 4x + 6y - 36 = 0 and x^(2) + y^(2) - 5x + 8y - 43 = 0 .

Suppose a x+b y+c=0 , where a ,ba n dc are in A P be normal to a family of circles. The equation of the circle of the family intersecting the circle x^2+y^2-4x-4y-1=0 orthogonally is (a) x^2+y^2-2x+4y-3=0 (b) x^2+y^2-2x+4y+3=0 (c) x^2+y^2+2x+4y+3=0 (d) x^2+y^2+2x-4y+3=0

The circle x^2 + y^2 - 2x - 4y + 1 = 0 and x^2 + y^2 + 4x + 4y - 1 = 0

Find the equation of the circle which passes through (1, 1) and cuts orthogonally each of the circles x^2 + y^2 - 8x - 2y + 16 = 0 and x^2 + y^2 - 4x -4y -1 = 0

The equation of the circel whose diameter is the common chord of the circles x ^(2) + y^(2) +2x +3y+2=0 and x ^(2) + y^(2) +2x -3y-4=0 is-