The equation of the image of the circle x2+y2−6x−4y+12=0  by the line mirror x+y−1=0  is

Center of the given circle C=(3,2) and radius r=1.Now the image of C(3,2) with respect to the line x+y-1=0 is (h,k) given byh-31=k-21=-23+2-1)2=-4 ⇒h,k=-1,-2 The image of the circle w.r.t. the line x+y-1=0 is x+12+y+22=1 ⇒x2+y2+2x+4y+4=0