\begin{definition}[Definition:Modified Bessel Function/Order]
Consider Bessel's modified equation:
:$x^2 \dfrac {\d^2 y} {\d x^2} + x \dfrac {\d y} {\d x} - \paren {x^2 + n^2} y = 0$
Let:
:$\map {I_n} x$ denote the modified Bessel function of the first kind
:$\map {K_n} x$ denote the modified Bessel function of the second kind
be the solutions of Bessel's modified equation as defined.
The parameter $n$ is known as the '''order''' of the modified Bessel function.
Category:Definitions/Bessel Functions
\end{definition}