The equation of the tangent to the curve y=x2 at (2,4) is, ‌
y+4
2
=2x So 4x−y−4=0 The equation of circle and tangent is, (x−2)2+(y−4)2+λ(4x−y−4)=0 since the circle passes through (0,1) then, (0−2)2+(1−4)2+λ(4(0)−1−4)‌‌=0 4+9−5λ‌‌=0 λ‌‌=‌
13
5
Substitute the value of λ in equation (I). (x−2)2+(y−4)2+‌