设圆心C(a,2-a)
|CA|=|CB|
(a-1)^2+(3-a)^2=(a+1)^2+(1-a)^2=R^2
-2a+1-6a+9=2a+1-2a+1
8a=8
a=1
C(1,1)
圆C:
(x-1)^2+(y-1)^2=4