c1:x2+y2−2x−6y+α=0 Then centre =(1,3) and radius (r)=√10−α Image of (1,3) w.r.t. line x−y+1=0 is (2,2) c2:5x2+5y2+10gx+10fy+38=0 or x2+y2+2gx+2fy+‌
38
5
=0 Then (−g,−f)=(2,2) ∴g=f=−2.........‌ (i) ‌ Radius of c2=r=√4+4−‌