Category:Definitions/Directrices of Ellipses

This category contains definitions related to Directrices of Ellipses.
Related results can be found in Category:Directrices of Ellipses.

Let $K$ be the ellipse specified as the locus of points $P$ to a straight line $D$ and a point $F$ such that $PD$ and $PF$ are related by the condition:

$\size {PF} = e \size {PD}$

where $0 < e < 1$.

The line $D$ is known as the directrix of the ellipse.