# Multi-line equation with image

I am trying to write an equation in which the right hand side is an image and the left hand side a mathematical expression. The only problem is that the expression is too long and it has to be separated in more than one line. I'd like to have a final result in which the mathematical expression is centered with respect the image. The closest output I got is with this code:

$$\vcenter{\hbox{\includegraphics[scale=0.2]{Image}}} = \begin{split} \frac{i k_g}{\Lambda}\;\delta^{a_1a_2}\bigg[\eta^{\nu\sigma}\Big(k_1^\mu k_2^\rho+k_1^\mu k_1^\rho\Big)+\eta^{\mu\sigma}\Big(k_1^\nu k_2^\rho+k_1^\nu k_1^\rho\Big)\\ &\eta^{\nu\rho}\Big(k_1^\sigma k_2^\mu+k_2^\sigma k_2^\mu\Big)+\eta^{\mu\rho}\Big(k_1^\sigma k_2^\nu+k_2^\sigma k_2^\nu\Big)\\ -\eta^{\rho\sigma}\Big(k_1^\mu k_2^\nu+k_1^\nu k_2^\mu\Big)-k_1\cdot k_2\Big(\eta^{\mu\rho}\eta^{\nu\sigma}+\eta^{\mu\sigma}\eta^{\nu\rho}\Big)\bigg]. \end{split}$$


But this is the output

As you can see the expression is not really aligned with the image and the second line is partially out of the page. How can I properly solve this problem?

• Welcome to TeX.SX! Would you please provide us with a MWE? – TeXnician Feb 8 '17 at 15:49

Use aligned; the picture can be vertically centered with gathered, which is less cumbersome than \vcenter.

\documentclass{article}

\usepackage{amsmath}
\usepackage{graphicx}

\begin{document}

Text before.
\begin{gathered} \includegraphics[width=4cm]{example-image} \end{gathered} = \begin{aligned}[t] &\frac{i k_g}{\Lambda}\delta^{a_1a_2}\bigl[ \eta^{\nu\sigma}(k_1^\mu k_2^\rho+k_1^\mu k_1^\rho)\\ &+\eta^{\mu\sigma}(k_1^\nu k_2^\rho+k_1^\nu k_1^\rho) \eta^{\nu\rho}(k_1^\sigma k_2^\mu+k_2^\sigma k_2^\mu)\\ &+\eta^{\mu\rho}(k_1^\sigma k_2^\nu+k_2^\sigma k_2^\nu) -\eta^{\rho\sigma}(k_1^\mu k_2^\nu+k_1^\nu k_2^\mu)\\ &-k_1\cdot k_2(\eta^{\mu\rho}\eta^{\nu\sigma}+ \eta^{\mu\sigma}\eta^{\nu\rho})\bigr]. \end{aligned}
Text after.

\end{document}


Another possibility is with adjustbox, if you wish a different relative placement.

\documentclass{article}

\usepackage{amsmath}
\usepackage{graphicx}

\begin{document}

Text before.
\begin{gathered} \setlength{\adjboxvtop}{1.2\baselineskip} \includegraphics[width=4cm,valign=t]{example-image} = \begin{aligned}[t] &\frac{i k_g}{\Lambda}\delta^{a_1a_2}\bigl[ \eta^{\nu\sigma}(k_1^\mu k_2^\rho+k_1^\mu k_1^\rho)\\ &+\eta^{\mu\sigma}(k_1^\nu k_2^\rho+k_1^\nu k_1^\rho) \eta^{\nu\rho}(k_1^\sigma k_2^\mu+k_2^\sigma k_2^\mu)\\ &+\eta^{\mu\rho}(k_1^\sigma k_2^\nu+k_2^\sigma k_2^\nu) -\eta^{\rho\sigma}(k_1^\mu k_2^\nu+k_1^\nu k_2^\mu)\\ &-k_1\cdot k_2(\eta^{\mu\rho}\eta^{\nu\sigma}+ \eta^{\mu\sigma}\eta^{\nu\rho})\bigr]. \end{aligned} \end{gathered}
Text after.

\end{document}


It can be done with split. Edit: Ooops! I had forgotten to \smash[b] the picture…

% My standard header for TeX.SX answers:
\documentclass[a4paper]{article} % To avoid confusion, let us explicitly
% declare the paper format.

\usepackage[T1]{fontenc}         % Not always necessary, but recommended.
% End of standard header.  What follows pertains to the problem at hand.

\usepackage{amsmath}
\usepackage{mwe}

\begin{document}

Text before.
$$\begin{split} \smash[b]{\vcenter{\hbox{\includegraphics[scale=0.2]{image}}}} = {}& \frac{i k_g} {\Lambda}\;\delta^{a_1a_2}\biggl[\eta^{\nu\sigma}\Bigl(k_1^\mu k_2^\rho+k_1^\mu k_1^\rho\Bigr)\\ &+\eta^{\mu\sigma}\Bigl(k_1^\nu k_2^\rho+k_1^\nu k_1^\rho\Bigr) \cdot \eta^{\nu\rho}\Bigl(k_1^\sigma k_2^\mu +k_2^\sigma k_2^\mu\Bigr)\\ &+\eta^{\mu\rho} \Bigl(k_1^\sigma k_2^\nu+k_2^\sigma k_2^\nu\Bigr)\\ &-\eta^{\rho\sigma}\Bigl(k_1^\mu k_2^\nu+k_1^\nu k_2^\mu\Bigr)- k_1\cdot k_2\Bigl(\eta^{\mu\rho}\eta^{\nu\sigma}+ \eta^{\mu\sigma}\eta^{\nu\rho}\Bigr)\biggr]. \end{split}$$
Text after.

\end{document}


I have chosen different points where to break the equation, IMHO they look much better. Also note that I have replaced \Big with \Bigl or \Bigr as appropriate, and the same for \bigg. Finally, note how the alignment point is specified.

This is the output:

The OP clarified that a different output was wanted, namely

In my humble opinion, this looks poorer than the output produced by the above code; in any case, it doesn’t pose any particular problem either:

% My standard header for TeX.SX answers:
\documentclass[a4paper]{article} % To avoid confusion, let us explicitly
% declare the paper format.

\usepackage[T1]{fontenc}         % Not always necessary, but recommended.
% End of standard header.  What follows pertains to the problem at hand.

\usepackage{amsmath}
\usepackage{mwe}

\begin{document}

Text before.
\vcenter{\hbox{\includegraphics[scale=0.2]{image}}} = \begin{aligned} &\frac{i k_g} {\Lambda}\;\delta^{a_1a_2}\biggl[\eta^{\nu\sigma}\Bigl(k_1^\mu k_2^\rho+k_1^\mu k_1^\rho\Bigr)\\ &+\eta^{\mu\sigma}\Bigl(k_1^\nu k_2^\rho+k_1^\nu k_1^\rho\Bigr) \cdot \eta^{\nu\rho}\Bigl(k_1^\sigma k_2^\mu +k_2^\sigma k_2^\mu\Bigr)\\ &+\eta^{\mu\rho} \Bigl(k_1^\sigma k_2^\nu+k_2^\sigma k_2^\nu\Bigr)\\ &-\eta^{\rho\sigma}\Bigl(k_1^\mu k_2^\nu+k_1^\nu k_2^\mu\Bigr)- k_1\cdot k_2\Bigl(\eta^{\mu\rho}\eta^{\nu\sigma}+ \eta^{\mu\sigma}\eta^{\nu\rho}\Bigr)\biggr]. \end{aligned}
Text after.

\end{document}