ich habe ein kleines Problem bei einer Formeldarstellung.
\documentclass[a4paper,10pt]{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
%opening
\title{Ein Titel}
\author{Der Author}
\begin{document}
\maketitle
\begin{abstract}
\end{abstract}
\section{Test}
\begin{equation}
\boxed{
\begin{alignat}{4}
\frac{\partial{a}_{1}}{\partial{t}} &= \frac{\partial^{2}{b_{M}\zeta_{1}}}{\partial{c^{2}}}+f\zeta_{2}
\hspace{2cm} \text{und}
&\frac{\partial{a}_{2}}{\partial{t}}& &&= \frac{\partial^{2}{b_{M}\zeta_{2}}}{\partial{c^{2}}}+f\zeta_{1} \\
%
\zeta_{1} &= \frac{\partial^{2}\psi_{1}}{\partial{z^{2}}}
\hspace{2cm} \text{und}
&\zeta_{2}& &&= \frac{\partial^{2}\psi_{2}}{\partial{z^{2}}} \\
%
u &= \frac{\partial\psi_{2}}{\partial{z}}
\hspace{2cm} \text{und}
&v& &&= -\frac{\partial\psi_{1}}{\partial{z}} \\
%
K_{M} &= (\kappa{z})^{2}\sqrt{\zeta_{1}^{2}+\zeta_{2}^{2}}
\end{alignat}
}
\end{equation}
\end{document}
Vielen Dank im Voraus!
Gruß[/code]
