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# hyperbola

A hyperbola is an open curve in the plane with two distinct branches, defined as the set of all points the difference of whose distances from two fixed points is a constant.

Algebraically, a hyperbola in the Cartesian plane with horizontal axis is a relation defined by an equation of the form

$\displaystyle\frac{(x-h)^2}{a^2}-\frac{(y-k)^2}{b^2}=r^2$

where the point $$(h,k)$$ is the center of the hyperbola. The major axis of the hyperbola is vertical if the $$y$$ term is positive and the $$x$$ term is negative.

Figure 1: A hyperbola in the Cartesian plane.

A hyperbola also has directices and important reflection properties. See the article on conics for an exposition.

Citation Info

• [MLA] “hyperbola.” Platonic Realms Interactive Mathematics Encyclopedia. Platonic Realms, 27 Mar 2013. Web. 27 Mar 2013. <http://platonicrealms.com/>
• [APA] hyperbola (27 Mar 2013). Retrieved 27 Mar 2013 from the Platonic Realms Interactive Mathematics Encyclopedia: http://platonicrealms.com/encyclopedia/hyperbola/