<?xml version="1.0" encoding="UTF-8"?>

<record version="18" id="4001">
 <title>beta function</title>
 <name>BetaFunction</name>
 <created>2003-02-09 03:44:12</created>
 <modified>2007-04-28 08:51:20</modified>
 <type>Definition</type>
 <creator id="2760" name="yark"/>
 <author id="2760" name="yark"/>
 <author id="1243" name="vmoraru"/>
 <classification>
	<category scheme="msc" code="33B15"/>
 </classification>
 <preamble>\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{amsfonts}
</preamble>
 <content>\PMlinkescapeword{property}
\PMlinkescapeword{side}

The \emph{beta function} is defined as
\[
  B(p,q) = \int_0^1 x^{p-1} (1-x)^{q-1} dx
\]
for any real numbers $p,q &gt; 0$.
For other complex values of $p$ and $q$,
we can define $B(p,q)$ by analytic continuation.

The beta function has the property
\[
  B(p,q) = \frac{\Gamma(p) \Gamma(q)}{\Gamma(p+q)}
\]
for all complex numbers $p$ and $q$ for which the right-hand side is defined.
Here $\Gamma$ is the gamma function.

Also,
\[
  B(p,q) = B(q,p)
\]
and
\[
  B({\textstyle\frac{1}{2},\frac{1}{2}}) = \pi.
\]

The beta function was first defined
by \PMlinkname{L.~Euler}{EulerLeonhard} in 1730,
and the name was given by J.~Binet.</content>
</record>
