# jemdoc: menu{MENU}{mathjax.html}, nodate, showsource
= MathJax
+jemdoc-rs+ uses [https://www.mathjax.org MathJax 4] for math rendering. MathJax is always included unless the +noeqs+ [directives.html directive] is set.
== Inline Math
The energy--mass equivalence $E = mc^2$ and Euler's identity $e^{i\pi} + 1 = 0$ are inline equations.
== Display Math
\(
\nabla \times \mathbf{E} = -\frac{\partial\mathbf{B}}{\partial t}
\)
== Aligned Equations
Use LaTeX's +aligned+ environment for multi-line equations without numbering:
\(
\begin{aligned}
\nabla \cdot \mathbf{D} &= \rho_f\\
\nabla \cdot \mathbf{B} &= 0\\
\nabla \times \mathbf{E} &= -\frac{\partial\mathbf{B}}{\partial t}\\
\nabla \times \mathbf{H} &= \mathbf{J}_f + \frac{\partial\mathbf{D}}{\partial t}
\end{aligned}
\)
== Numbered Equations
Use LaTeX's +equation+ environment to number a block as a single equation:
\(
\begin{equation}
\begin{aligned}
\nabla \cdot \mathbf{D} &= \rho_f\\
\nabla \cdot \mathbf{B} &= 0\\
\nabla \times \mathbf{E} &= -\frac{\partial\mathbf{B}}{\partial t}\\
\nabla \times \mathbf{H} &= \mathbf{J}_f + \frac{\partial\mathbf{D}}{\partial t}
\end{aligned}
\end{equation}
\)
Use +align+ to number each equation individually:
\(
\begin{align}
\nabla \cdot \mathbf{D} &= \rho_f\label{eq:D}\\
\nabla \cdot \mathbf{B} &= 0\label{eq:B}\\
\nabla \times \mathbf{E} &= -\frac{\partial\mathbf{B}}{\partial t}\label{eq:E}\\
\nabla \times \mathbf{H} &= \mathbf{J}_f + \frac{\partial\mathbf{D}}{\partial t}\label{eq:H}
\end{align}
\)
== Cross-Referencing
The curl equations are Eqs.~$\eqref{eq:E}$ and $\eqref{eq:H}$.