focal conic
1Conic section — Types of conic sections: 1. Parabola 2. Circle and ellipse 3. Hyperbola …
2conic section — Geom. a curve formed by the intersection of a plane with a right circular cone; an ellipse, a circle, a parabola, or a hyperbola. Also called conic. [1655 65] * * * Any two dimensional curve traced by the intersection of a right circular cone… …
3Focal point — A focal point may mean: * Focus (optics), the point at which initially collimated rays of light meet after passing through a convex lens, or reflecting off of a concave mirror. * In mathematics: ** Focus (geometry), a special point used in… …
4Hyperbola — This article is about a geometrical curve, a conic section. For the term used in rhetoric, see Hyperbole …
5Parabola — For other uses, see Parabola (disambiguation). A parabola …
6Ellipse — Elliptical redirects here. For the exercise machine, see Elliptical trainer. This article is about the geometric figure. For other uses, see Ellipse (disambiguation). Not to be confused with ellipsis. An ellipse obtained as the intersection of a… …
7Dandelin spheres — are touching the light blue plane that intersects the cone. In geometry, the Dandelin spheres are one or two spheres that are tangent both to a plane and to a cone that intersects the plane. The intersection of the cone and the plane is a conic… …
8Apollonius of Perga — Apollonius of Perga. Apollonius of Perga [Pergaeus] (Ancient Greek: Ἀπολλώνιος) (ca. 262 BC – ca. 190 BC) was a Greek geometer and astronomer noted for his writings on conic sections. His innovative methodology and terminology, especially in the… …
9History of the telescope — The earliest known working telescopes appeared in 1608 and are credited to Hans Lippershey and Zacharias Janssen, spectacle makers in Middelburg, and Jacob Metius of Alkmaar. The design of these early refracting telescopes consisted of a convex… …
10Eccentricity (mathematics) — In mathematics, the eccentricity, denoted e or varepsilon, is a parameter associated with every conic section. It can be thought of as a measure of how much the conic section deviates from being circular.In particular, * The eccentricity of a… …
