# How can I split this equation?

Does anyone know how to split this equation in two lines?

\begin{equation*}

\iint_S \eta = \iint_S \left[F(x(u,v), y(u,v), z(u,v)) \ \frac{\partial(x,y)}{\partial(u,v)} + G(x(u,v), y(u,v), z(u,v)) \ \frac{\partial(x,y)}{\partial(u,v)}+H(x(u,v), y(u,v), z(u,v)) \ \frac{\partial(x,y)}{\partial(u,v)} \right]

\end{equation*}


I would like the equation to look like this

\begin{equation*}

\iint_S \eta = \iint_S \left[F(x(u,v), y(u,v), z(u,v)) \ \frac{\partial(x,y)}{\partial(u,v)} + G(x(u,v), y(u,v), z(u,v)) \ \frac{\partial(x,y)}{\partial(u,v)}+

H(x(u,v), y(u,v), z(u,v)) \ \frac{\partial(x,y)}{\partial(u,v)} \right]

\end{equation*}


by adding a linebreak or whatever necessary right at the +H(x(u,v)...

Please, bear in mind that I'm pretty new to latex

-
Welcome to TeX.SX. You must learn to write a question using our format rules view here – skpblack Aug 6 '14 at 15:29
The split environment may work for this. See Herbert Voß, Math mode, specifically equation II-86 on p.55. – Mike Renfro Aug 6 '14 at 15:49

I would use the multline* environment, as there's to align naturally:

\documentclass[a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage[nomarginpar,  showframe]{geometry}
\usepackage{mathtools}

\begin{document}

\begin{multline*}
\iint_S \eta = \iint_S \left[F(x(u,v), y(u,v), z(u,v)) \frac{\partial(x,y)}{\partial(u,v)} \right. \\\left.{} + G(x(u,v), y(u,v), z(u,v)) \frac{\partial(x,y)}{\partial(u,v)}+ H(x(u,v), y(u,v), z(u,v))\frac{\partial(x,y)}{\partial(u,v)} \right]
\end{multline*}

\end{document}


-

Try the align environment from the amsmath package:

\documentclass{article}
\usepackage{amsmath}

\begin{document}

\begin{align*}
\iint_S \eta  = \iint_S \Bigl[& F(x(u,v), y(u,v), z(u,v)) \ \frac{\partial(x,y)}{\partial(u,v)}
+  G(x(u,v), y(u,v), z(u,v)) \ \frac{\partial(x,y)}{\partial(u,v)}\\
&  + H(x(u,v), y(u,v), z(u,v)) \ \frac{\partial(x,y)}{\partial(u,v)} \Bigr]
\end{align*}

\end{document}

-

You can choose this alternative.

    \begin{equation*}
\begin{split}
\iint_S \eta =& \iint_S \Bigl\{F(x(u,v), y(u,v), z(u,v)) \ \frac{\partial(x,y)}{\partial(u,v)} + G(x(u,v), y(u,v), z(u,v))  \frac{\partial(x,y)} \partial(u,v)}+
\\
&H(x(u,v), y(u,v), z(u,v)) \ \frac{\partial(x,y)}{\partial(u,v)} \Bigr\}
\end{split}
\end{equation*}

-