A circle is concentric with circle `x^2+y^2-2x+4y-20=0` . If perimeter of the semicircle is 36 then the equation of the circle is: `[u s epi=22//7]` `x^2+y^2-2x+4y-44=0` `(x-1)^2+(y+2)^2=(126//11)^2` `x^2+y^2-2x+4y-43=0` `x^2=y^2-2x+4y-49=0`

Equation of unit circle concentric with circle x^(2)+y^(2)+8x+4y-8=0 is

Find the parametric equation of the circles : x^2 + y^2 - 2x+4y-4=0

Find the parametric equation of the circles : x^2 + y^2 + 2x - 4y - 1 =0

The tangent of the circle x^(2)+y^(2)-2x-4y-20=0 at (1,7) meets the y -axis at the point

Point on the circle x^(2)+y^(2)-2x+4y-4=0 which is nearest to the line y=2x+11 is :

Write the parametric equations of the circle x^(2)+y^(2)-2x-4y-4=0

If the circle x^2+y^2-6x-4y+9=0 bisects the circumference of the circle x^2+y^2-8x-6y+a=0 , then the value of a is ____

From a point R(5,8), two tangents RPandRQ are drawn to a given circle S=0 whose radius is 5. If the circumcenter of triangle PQR is (2,3), then the equation of the circle S=0 is x^(2)+y^(2)+2x+4y-10=0x^(2)+y^(2)+x+2y-10=0x^(2)+y^(2)-x+2y-20=0x^(2)+y^(2)+4x-6y-12=0