Category:Conic Sections

This category contains results about Conic Sections.
Definitions specific to this category can be found in Definitions/Conic Sections.

A conic section is a plane curve which can be specified in terms of:

a given straight line $D$ known as the directrix

a given point $F$ known as a focus

a given constant $\epsilon$ known as the eccentricity.

Let $K$ be the locus of points $b$ such that the distance $p$ from $b$ to $D$ and the distance $q$ from $b$ to $F$ are related by the condition:

$(1): \quad q = \epsilon \, p$

Then $K$ is a conic section.

Equation $(1)$ is known as the focus-directrix property of $K$.