Question

The distance between the chords of contact of the tangents to the circle x² + y² + 2gx + 2fy + c = 0 from the origin and the point (g, f) is

(a) g² + f²

(b) \(\frac12(g^2+f^2+c)\)

(c) \(\frac12\left(\frac{g^2+f^2+c}{\sqrt{g^2 + f^2}}\right)\)

(d) \(\frac12\frac{g^2+f^2-c}{\sqrt{g^2 + f^2}}\)

Answer 1

Equation of chord of contact to the circle from (x₁, y₁) is