Inline math

• $x = 1$.
• \( x = 2 \).
• (x = 3).

Full line math

\[x = 4\]

[x = 5]

$$ x = 6$$

Environments

First align:

\begin{align} x&=2 \\
y&=3 \end{align}

Then align*:

\begin{align*} x&=2 \\
y&=3 \end{align*}

Finally aligned:

$$ \begin{aligned} x&=2 \\
y&=3 \end{aligned} $$

Labels

\begin{equation} \label{eq_four} 4 \end{equation}

See equation \ref{eq_four}.

Definitions

New command

How to do in mathjax

$\newcommand{\NN}{\mathbb{N}}$

Let $x\in\NN$.