# Align equations inside tabular

How can I align equations inside tabular? I want to place few lines of equation by side of the picture. But it turns out that I cannot use \& in order to shift equals signs to be one under another.

\documentclass{article}      % Specifies the document class

\usepackage{amsmath, amsfonts, mathtools, xfrac, empheq}
\usepackage{caption}

\begin{document}       % End of preamble and beginning of text.
\begin{tabular}{l r}
\begin{minipage}{0.6\textwidth}
\begin{align}
V^\pi = E_\pi \{ R_t \mid s_t = s \} \\
= E_\pi \left \{ \sum\limits_{k=0}^\infty \gamma^k r_{t+k+1} \mid s_t = s \right \}  \notag \\
= E_\pi \left \{ r_{t+1} + \gamma \sum_{k=0}^\infty \gamma^k r_{t+k+2} \mid s_t =s \right\} \notag
\end{align}
\end{minipage}
&
\begin{minipage}{0.4\textwidth}
%\includegraphics[width=\textwidth]{olcar_L11-8}
\captionof{figure}{Backup diagram}
\end{minipage}
\end{tabular}

\end{document}


I would like it to like this:

• You could put a {} around the minipage but simpler just remove the outer tabular which isn't doing anything very useful, just put the two minpages on a line separated by (say) \hfill (edit as written your line is overfull as your minipages add up to \linewidth but you have a paragraph indentation on the left and 4\tabcolsep from the padding added by the outer tabular. – David Carlisle Dec 4 '13 at 14:52

Overfull \hbox (39.00003pt too wide) in paragraph at lines 8--22


Due to paragraph indentation and 4 \tabcolsep (15+4*6=39pt).

If you simplify the markup, removing the tabular, the line fits the page, and you can use align with no problems:

\documentclass{article}      % Specifies the document class

\usepackage{amsmath, amsfonts, mathtools, xfrac, empheq}
\usepackage{caption}

\begin{document}       % End of preamble and beginning of text.

\noindent
\begin{minipage}{0.6\textwidth}
\begin{align}
V^\pi &= E_\pi \{ R_t \mid s_t = s \} \\
&= E_\pi \left \{ \sum\limits_{k=0}^\infty \gamma^k r_{t+k+1} \mid s_t = s \right \}  \notag \\
&= E_\pi \left \{ r_{t+1} + \gamma \sum_{k=0}^\infty \gamma^k r_{t+k+2} \mid s_t =s \right\} \notag
\end{align}
\end{minipage}\hfill
\begin{minipage}{0.4\textwidth}
%\includegraphics[width=\textwidth]{olcar_L11-8}
\captionof{figure}{Backup diagram}
\end{minipage}

\end{document}


If we use aligned instead of align, it is accepted inside tabular. I would suggest replacing \left and \right by a proper, smaller braces.

Edit, according to the request from the comment: Please observe, that aligned doesn't call math mode, hence such mode should be activated.

\documentclass{article}      % Specifies the document class

%\usepackage{amsmath, amsfonts, mathtools, xfrac, empheq}
\usepackage{amsmath, amsfonts, empheq}
\usepackage{caption}

\begin{document}       % End of preamble and beginning of text.
\begin{tabular}{l r}
\begin{minipage}{0.6\textwidth}
% PS %\begin{align} \begin{aligned} V^\pi &= E_\pi \{ R_t \mid s_t = s \} \\ &= E_\pi \left \{ \sum\limits_{k=0}^\infty \gamma^k r_{t+k+1} \mid s_t = s \right \} \notag \\ &= E_\pi \left \{ r_{t+1} + \gamma \sum_{k=0}^\infty \gamma^k r_{t+k+2} \mid s_t =s \right\} \notag %\end{align} \end{aligned}
\end{minipage}
&
\begin{minipage}{0.4\textwidth}
%\includegraphics[width=\textwidth]{olcar_L11-8}
\captionof{figure}{Backup diagram}
\end{minipage}
\end{tabular}

\end{document}


• Great answer. Only comment here is that aligned must be applied within a math environment. You have done this with \$ but it is not immediately obvious that the align is inside for anyone else who is looking. – twerdster Nov 29 '14 at 3:37