= Apollonius of Perga
{c}
<Apollonius of Perga> developed a systematic theory of <conic sections>. His surviving Conics studies the geometry of the <ellipse>, <parabola> and <hyperbola>, including their tangents and diameter relations.<Treatise on Conic Sections by Apollonius of Perga (Heath edition)>[Primary Conics text, Book I; edition introduction distinguishes the ancient work from modern notation]{ref}
A single construction—cutting a <cone> by a <plane>—produces these different families of curves. Apollonius's work organizes their properties through geometric relations rather than modern Cartesian equations. Translating between those viewpoints helps explain why an equation such as $y^2=4ax$ describes a <parabola> without attributing coordinate notation to the ancient author.
Back to article page
