$\sqrt{3x-1}+(1+x)^2$

$$\begin{array}{c}

\nabla \times \vec{\mathbf{B}} -\, \frac1c\, \frac{\partial\vec{\mathbf{E}}}{\partial t} &
= \frac{4\pi}{c}\vec{\mathbf{j}} \nabla \cdot \vec{\mathbf{E}} & = 4 \pi \rho \

\nabla \times \vec{\mathbf{E}}\, +\, \frac1c\, \frac{\partial\vec{\mathbf{B}}}{\partial t} & = \vec{\mathbf{0}} \

\nabla \cdot \vec{\mathbf{B}} & = 0

\end{array}$$

$$
H=-\sum{i=1}^N (\sigma{i}^x \sigma{i+1}^x+g \sigma{i}^z)
$$

$$
f(n) = \begin{cases}
\frac{n}{2},
& \text{if } n\text{ is even}
\ 3n+1, & \text{if } n\text{ is odd}
\end{cases}
$$

$F=Wx$