Math & Science ⇒ Same label for two different placed equation?

[Yue]

I have written the same equation twice, one in the text, other in the appendix. Can I label them both so that they show the same equation number?

[localghost]

Code: Select all

\documentclass[english]{scrartcl}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{babel}
\usepackage{amsmath}

\begin{document}
  \section{First Section}
    An equation in the document seen as
    \begin{equation}\label{eqn:einstein}
      E=mc^2
    \end{equation}
    Followed by some equations just for demonstration
    \begin{subequations}\label{eqn:binomi}
      \begin{align}
        (a+b)^2 &= a^2+2ab+b^2 \label{subeqn-1:binomi} \\
        (a+b)^2 &= a^2-2ab+b^2 \label{subeqn-2:binomi} \\
        (a+b)(a-b) &= a^2-b^2 \label{subeqn-3:binomi}
      \end{align}
    \end{subequations}

  \appendix
  \section{First Appendix Section}
    And now the same equation again
    \begin{equation}
      E=mc^2 \tag{\ref{eqn:einstein}}
    \end{equation}
    tagged with the same number.
\end{document}

Best regards
Thorsten

[Yue]

Thx, but my document gives errors, so here is another question:
Can I use \include{appendix} in my main document and make a new page called appendix.tex and start that page with \appendix?

[localghost]

[...] but my document gives errors [...]

Be precise and show concrete error messages from the log.

[...] Can I use \include{appendix} in my main document and make a new page called appendix.tex and start that page with \appendix?

Of course. You only need one more compiler. In the first run the file »appendix.aux« is created. In the second run the compiler will retrieve all necessary information from that file to get the references right.

[Yue]

I mean, is this the correct way to make an appendix? I got all my chapters using \include{chaptername}. Can I do the same with appendix?

[localghost]

Why don't you just test it? All you can get is an error message. Your machine won't be blown up.

[Yue]

It says 65 errors, so I am trying to figure it out

[localghost]

I could build a working example, but I think it's your turn to show the opposite [1]. Otherwise we won't get closer to a solution.

[1] Creating a LaTeX Minimal Example

[Yue]

I think I figured it out,
\appendix
\include{butter}
\include{bibliographi}
etc.
Thx for your patience, it appears the Appendix only changes nummeration of the chapters and sections