The square of the length of the tangent from (3,−4) to the circle x2+y2−4x−6y+3=0 is
The equation of circle is x2+y2−4x−6y+3=0.
The length of the tangent from point (3,−4) is,
√x21+y21+gx1+hy1−r
√(3)2+(−4)2−4(3)−6(−4)+3
=√40
The square of this length of the tangent is 40.