∵‌PA=PB ∴‌△OAP≅△OPB. ( O is centre of circle ‌x2+y2−4x−4y−8=0 ‌r=√4+4+8=4) ∵ Equation of circle at P and radius 4 is (x−2)2+(y+2)2=22 ∴AB is common chord ∴ Equation is S1−S2=0 ‌(x2+y2−4x−4y−8) ‌−(x2+y2−4x+4y+4+4−4)=0 ‌⇒‌‌−8y−8−4=0 ‌⇒‌‌8y+12=0 ‌2y+3=0
