# How to use LaTeX in Markdown

Many *Markdown* processors are capable to interpret *LaTeX*’s *math* mode commands in order to display a broad variaty of mathematical expressions. For some processors, this support is already enabled by default or you have to enable the so-called *MathJax* support. *MathJax* ꜛ is a display engine based on *JavaScript*, that renders mathematical *LaTeX* expressions into a PNG, that is then displayed in the preview mode of your *Markdown* editor or web browser.

While some *Markdown* processors are equipped with such support, others are not. Also web browser based *Markdown* solutions like *Jekyll* websites lack such built-in support. Nevertheless, also for these cases it’s actually very easy to get *MathJax* running. The only thing you need to do is to add the following HTML command to your *Markdown* document:

```
<script
src="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"
type="text/javascript">
</script>
```

** Jekyll websites**: Just add the HTML code to your layout definition files, e.g., single.html or post.html, and

*MathJax*support gets enabled on all your pages that use these layouts.

** Jupyter notebooks** come with enabled

*MathJAX*support by default ꜛ.

## How to use *LaTeX* in your *Markdown* document

The solution above enables the following syntax to use *LaTeX* within your *Markdown* document:

`$$ your equation $$`

Place this expression in the middle of your text for *inline* equations. Place the expression into its own line and insert one empty line to the previous paragraph for *display style* equations:

```
This is an inline equation: $$V_{sphere} = \frac{4}{3}\pi r^3$$,<br>
followed by a display style equation:
$$V_{sphere} = \frac{4}{3}\pi r^3$$
```

* * This is an inline equation: \(V_{sphere} = \frac{4}{3}\pi r^3\),

* * followed by a display style equation:

**Info**: You can also use `\\( your equation \\)`

and `\\[ your equation \\]`

for *inline* and *display style* equations, respectively. The HTML code above enables the syntax with the `$$`

signs with automatic distinction between *inline* and *display style* equations.

**Info**: You can use all *LaTeX* *math* mode expressions and commands, that are covered by the default *LaTeX* and the *amsmath* packages. The *LaTeX* guide on this website contains some commonly used *math* mode expressions.

To assign numbers to your equations, use the `\tag{number}`

command:

```
$$
\begin{align}
\tag{1.1}
V_{sphere} = \frac{4}{3}\pi r^3
\end{align}
$$
```

## Extended *MathJax* support

Just recently I have discovered an extended version of the HTML command above by Sebastian Flennerhag ꜛ:

```
<script type="text/javascript"
src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-AMS_CHTML">
</script>
<script type="text/x-mathjax-config">
MathJax.Hub.Config({
tex2jax: {
inlineMath: [['$','$'], ['\\(','\\)']],
processEscapes: true},
jax: ["input/TeX","input/MathML","input/AsciiMath","output/CommonHTML"],
extensions: ["tex2jax.js","mml2jax.js","asciimath2jax.js","MathMenu.js","MathZoom.js","AssistiveMML.js", "[Contrib]/a11y/accessibility-menu.js"],
TeX: {
extensions: ["AMSmath.js","AMSsymbols.js","noErrors.js","noUndefined.js"],
equationNumbers: {
autoNumber: "AMS"
}
}
});
</script>
```

This code enhances the *LaTeX* usage within *Markdown* documents by the following functions:

*Inline*equations can be defined by a single`$`

sign, which corresponds to the original*LaTeX*syntax, e.g,`$V_{sphere} = \frac{4}{3}\pi r^3$`

.- Equation numbering is performed automatically in the
`equation`

,`eqnarray`

and`align`

environment. You can even reference equations with the*LaTeX*command`\eqref{label}`

:

```
\begin{align}
V_{sphere} = \frac{4}{3}\pi r^3 \label{eq:test1}
\end{align}
In Eq. $\eqref{eq:test1}$ you can see...while in Eq. $\eqref{eq:test2}$...
\begin{align}
V_{cube} = l w h \label{eq:test2}
\end{align}
```

* * In Eq. $\eqref{eq:test1}$ you can see…while in Eq. $\eqref{eq:test2}$…

The *MathJax* documentation ꜛ contains more information about the settings and how to further extend the *MathJax* support within your *Markdown* documents.