Is there a variant of split
environment from amsmath
package which would allow for two aligned equations in a row? I want to format two pairs of Maxwell equations in two rows and put single equation number between the rows. Unfortunetely, split
allows only one alignment tab &
in a row, and I need three as in the following example:
\documentclass{article}
\usepackage{amsmath}
\DeclareMathOperator{\Div}{div}
\DeclareMathOperator{\Rot}{rot}
\begin{document}
\begin{align}
\label{18.1:1}
%\begin{split}
\Rot\vec{E} &=-\frac{1}{c}\parder{\vec{B}}{t}
,
&
\Div\vec{B} &=0,
\\
\label{18.1:2}
\Rot\vec{B} &=\frac{1}{c}\parder{\vec{E}}{t}
+\frac{4\pi}{c}\,\vec{j}
,
&
\Div\vec{E} &=4\pi\rho_{\varepsilon }
%\end{split}
\end{align}
\end{document}
Here every row has its own number.
\parder
is nowhere defined. Also, you may want to use a more descriptive name for your labels, and it's best to precede punctuation marks such commas and full stops by a\,
.\parder
is defined as:\newcommand{\parder}[2]{\frac{\partial {#1}}{\partial {#2}}}
.parder
.