Question 934426
Find center and radius of the circle.  Maybe you do not need the radius.
Find slope of the line containing the circle's center and point A.
Form the negative reciprocal of that line, and call this slope, m.


Find using point-slope form, the linear equation using point A(2,-1),
{{{y-(-1)=m(x-2)}}}, and simplify or arrange into the form you want.


You need to complete the square on the equation of the circle and put into standard form so you can directly read the x and y coordinates for the center of this circle.