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Viewing Version 8 of 'conjugate hyperbola'
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Title of object: conjugate hyperbola
Canonical Name: ConjugateHyperbola
Type: Definition

Created on: 2004-09-28 07:19:07
Modified on: 2006-02-14 07:16:05

Creator: pahio
Modifier: pahio
Author: pahio
Author: drini

Classification: msc:51N20
Defines: transverse axis, conjugate axis, mixed term

Revision comment (for changes between this and next version):

page images rendering fixed

Preamble:

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\usepackage{amssymb}
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Content:

The simplest form of the equation presenting a hyperbola (without the \PMlinkescapetext{{\em mixed $xy$-term}}) in a rectangular coordinate system is got when the coordinate axes coincide with the \PMlinkescapetext{principal} axes of the hyperbola, and it has the form
\begin{align}
\frac{x^2}{a^2}-\frac{y^2}{b^2} = 1.
\end{align}
Here, $a \,(>0)$ is the \PMlinkescapetext{length of the {\em transverse semiaxis}} and $b \,(>0)$ the \PMlinkescapetext{length of the {\em conjugate semiaxis}} of the hyperbola.

The equation
\begin{align}
\frac{y^2}{b^2}-\frac{x^2}{a^2} = 1
\end{align}
or
$$\frac{x^2}{a^2}-\frac{y^2}{b^2} = -1.$$
presents the {\em conjugate hyperbola} of (1).\, Its transverse axis is the conjugate axis of (1) and its conjugate axis the transverse axis of (1).\, Both hyperbolas are conjugate hyperbolas of each other.\, They have the common asymptotes
$$\frac{x^2}{a^2}-\frac{y^2}{b^2} = 0$$
and their foci are on the circle \,$x^2+y^2 = a^2+b^2$.
\begin{center}
\includegraphics{conjughyperb}
\end{center}