# Aligning formula problem

\documentclass{article}

\usepackage{amsmath}

\begin{document}

\begin{align*}
y ={}& \frac{1}{n!} \left\lbrace \int + f(a) \right. \\
&\left. \vphantom{\int} + [h(u)+\phi(x)] + C \right\rbrace
\end{align*}
\end{document}


How to align the plus sign with fraction? Thanks.

• (1) welcome, (2) as always on this site please provide a full minimal example, then it is a lot easier for other to test your code. (3) Drop the use of \left...\right and use the manual ones instead (\big\Big\bigg\Bigg), then the alignment can be placed inside the construction and aligning on the + is easy. – daleif Dec 10 '18 at 9:18
• Thank you.If I must use the left/right pair, how to modify the code? – August Dec 10 '18 at 9:23
• Sorry to ask so naively, but are you sure you want to type \int + in this combination? – marmot Dec 10 '18 at 10:09

Alignment is not really necessary and multline might do the job. If you feel that alignment is important, here are three proposals.

\documentclass{article}

\usepackage{amsmath}

\begin{document}

The following aligns the + with the fraction
\begin{equation*}
\begin{split}
y ={} & \frac{1}{n!} \biggl\lbrace \int + f(a) \\
& {} + [h(u)+\phi(x)] + C \biggr\rbrace
\end{split}
\end{equation*}
but with a slight offset; with the following the
offset is removed
\begin{equation*}
\begin{split}
y ={} & \frac{1}{n!} \biggl\lbrace \int + f(a) \\
& {\mspace{-\medmuskip}} + [h(u)+\phi(x)] + C \biggr\rbrace
\end{split}
\end{equation*}
However, I'd align with the integral sign
\begin{equation*}
\begin{split}
y = \frac{1}{n!} \biggl\lbrace &\!\int + f(a) \\
& {\mspace{-\medmuskip}} + [h(u)+\phi(x)] + C \biggr\rbrace
\end{split}
\end{equation*}

\end{document}


• Thank you. If I must use the left/right pair, how to modify the code? – August Dec 10 '18 at 10:17
• @August As you were doing, with \vphantom. – egreg Dec 10 '18 at 11:48
• Does “\mspace{-\medmuskip}” similar to “\!”, add some negative offset? I have used “\!” achieve the same result, it’s manual method. – August Dec 10 '18 at 14:02
• @August \! adds \mspace{-\thinmuskip}, but a \medmuskip is added in front of a binary operation symbol and it is larger than \thinmuskip. – egreg Dec 10 '18 at 14:03
• Your method is also worked, thank you very much. – August Dec 10 '18 at 14:10

try

\begin{align*}
y &= \frac{1}{n!} \left\lbrace \int + f(a) \right. \\
&\phantom{=} \left. \vphantom{\int} + [h(u)+\phi(x)] + C \right\rbrace
\end{align*}

• Thank you. The plus sign wasn’t aligning with fraction . – August Dec 10 '18 at 9:39

You do not require alignment here (which is why you are needing \phantom etc to hide the alignment point) you just have a line that needs to be broken (so I assume you have a narrow text width) something like:

\documentclass[twocolumn,a5paper]{article}

\usepackage{amsmath}

\begin{document}

\begin{multline*}
y =\frac{1}{n!} \Bigl\lbrace \int + f(a)  \\
{} + [h(u)+\phi(x)] + C \Bigr\rbrace
\end{multline*}
\end{document}

• Thank you. I use vphantom to keep same sized big left/right brace.If I must use the left/right pair, how to modify the code? – August Dec 10 '18 at 10:13
• you can still use \left . with the vphantom if you wish (but usually using \Bigl (for some fixed name size is better) that change is separate from teh suggestion to change align to multline – David Carlisle Dec 10 '18 at 12:28