# 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:

\begin{equation}
\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}
\end{equation}


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{equation}
\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}
\end{equation}
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{equation}
\begin{gathered}
\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}
\end{equation}
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{equation}
\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}
\end{equation}
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.
\begin{equation}
\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}
\end{equation}
Text after.

\end{document}