Origin+of+the+Ellipse+by+Cyrus

Conic Sections: Ellipses A History An ellipse occurs when a plane intercepts a cone thus resulting in a plane curve. The Greek mathematician known as Menaechmus (the tutor of Alexander the Great) is credited with first studying the ellipse. Later, Pappus introduced the concept of the focus and the directrix. Keplar hypothesized that a comet rotated around the sun in an elliptical manner. And by conveying the sun as the focus in his 1609 findings, Keplar succesfully used the conic concept of ellipses in astro-physics. In Cartesian coordinates, ellipses are expressed as: Equations in an Ellipse