Pair of Tangents from a Point on the Minor Axis

Pair of Tangents from a Point on the Minor Axis

For:

$$P(0,y_1)$$

the pair of tangents is:

$$\left(\frac{yy_1}{b^2}-1\right)^2=\left(\frac{y_1^2}{b^2}-1\right)\left(\frac{x^2}{a^2}+\frac{y^2}{b^2}-1\right)$$

Usage

- Used when the combined equation of the two tangents from a point on the minor axis is required.