Product of Distances from the Asymptotes
For a point $$P(x,y)$$ on:
$$\frac{x^2}{a^2}-\frac{y^2}{b^2}=1$$
the product of its perpendicular distances from the two asymptotes is constant:
$$d_1d_2=\frac{a^2b^2}{a^2+b^2}$$
Usage
- Used in locus and distance problems involving the asymptotes.