Length of a Focal Chord

Length of a Focal Chord

If a focal chord has endpoint parameters $$\theta_1,\theta_2$$, its length can be obtained from the endpoint coordinates:

$$L=\sqrt{a^2(\cos\theta_1-\cos\theta_2)^2+b^2(\sin\theta_1-\sin\theta_2)^2}$$

Usage

- Used to calculate the length of a focal chord when its endpoint parameters are known.