Given that normal cuts the circle at points A(3,4) and B(−1,−2) . As we know, normal line is always passing through the centre of the circle and AB is the diameter of the circle. Therefore, A and B are the end points of a diameter. ∴ Required equation of circle is (x−3)(x+1)+(y−4)(y+2)=0 ⇒x2−2x−3+y2−2y−8=0 ⇒x2+y2−2x−2y−11=0