[Tex/LaTex] Difference between equation and equation* enviroment

environmentsequationsmath-mode

I am pretty new to Latex and I was wondering what is the difference between:

\begin{equation}
\end{equation}

and

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

I am always using the first one, but in what instance would you use the latter, or is there any difference between them at all?

I couldn't find any answers of this question on this forum.

Best Answer

The non-starred version provides a numbered equation, which you can easily refer to with \label and \ref. The starred version does not provide the equation number, while keeping the same format, and has an equivalent in \[ ... \].

\documentclass{article}

\usepackage{amsmath}

\begin{document}

The non-starred version provides a numbered equation, which you can easily refer to with \verb^\ref^, like so: \ref{euler}
\begin{equation}
    e^{i\pi} + 1 = 0
    \label{euler}
\end{equation}
The starred version does not provide the equation number, while keeping the same format.
\begin{equation*}
    e^{i\pi} + 1 = 0
\end{equation*}
Unnumbered, displayed equations can also be obtained with \verb^\[ ... \]^.
\[
    e^{i\pi} + 1 = 0
\]

\end{document}

Related Solutions

[Tex/LaTex] the difference between \newenvironment and \newenvironment*

The relation is the same as that between \newcommand and \newcommand*, which is covered in What's the difference between \newcommand and \newcommand*?

There's no influence on the environment's behavior, except as regards to the arguments to \begin{envname}.

Specifically, if you say

\newenvironment{foo}[1]
 {something with #1}
 {something else}

you're allowed to say

\begin{foo}{An argument 

  with a blank line}
The environment's contents

With perhaps a blank line
\end{foo}

while \newenvironment*{foo} wouldn't allow this and the argument should not contain any blank line (or \par command), but the environment's contents has no limitation (other than those possibly imposed by its definition).

[Tex/LaTex] What’s the difference between split and aligned

One important difference is that split obeys to the centertags (default) or tbtags option. Here is an example

\documentclass[twocolumn]{article}
\usepackage[
%  tbtags,
%  leqno,
]{amsmath}
\begin{document}
\begin{align}
a&=b\\
\begin{split}
c&=d+{}\\
 &=e+{}\\
 &=f
\end{split}\\
g&=h
\end{align}
\end{document}

enter image description here

Now the same with uncommented tbtags:

enter image description here

Now also leqno is uncommented:

enter image description here

To the contrary, aligned will have the equation number according to the vertical alignment option: centered for \begin{aligned}...\end{aligned}, at the top for \begin{aligned}[t]...\end{aligned}, at the bottom for \begin{aligned}[b]...\end{aligned}. Thus it's better to use split whenever possible, if equation numbers are involved. (I rarely use equation numbers, so I usually don't bother.)

Best Answer

Related Solutions

[Tex/LaTex] the difference between \newenvironment and \newenvironment*

[Tex/LaTex] What’s the difference between split and aligned

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