Find the length of the tangent from (h,k)(h, k)(h,k) to the circle x2+y2+2gx+2fy+c=0x^2 + y^2 + 2gx + 2fy + c = 0x2+y2+2gx+2fy+c=0.
h2+k2+2gh+2fk+c\sqrt{h^2 + k^2 + 2gh + 2fk + c}h2+k2+2gh+2fk+c
h2+k2−c\sqrt{h^2 + k^2 - c}h2+k2−c
g2+f2−c\sqrt{g^2 + f^2 - c}g2+f2−c
h+k+ch + k + ch+k+c