latex
随便写写公式玩。。。
$$\begin{aligned}\nabla \times \vec{\mathbf{B}} -, \frac1c,\frac{\partial\vec{\mathbf{E}}}{\partial t} & = \frac{4\pi}{c}\vec{\mathbf{j}} \ \nabla \cdot \vec{\mathbf{E}} & = 4 \pi \rho \\nabla \times \vec{\mathbf{E}}, +, \frac1c, \frac{\partial\vec{\mathbf{B}}}{\partial t} & = \vec{\mathbf{0}} \\nabla \cdot \vec{\mathbf{B}} & = 0 \end{aligned}$$
$$\left( \sum_{k=1}^n a_k b_k \right)^2 \leq \left( \sum_{k=1}^n a_k^2 \right) \left( \sum_{k=1}^n b_k^2 \right)$$
$$\sqrt[2]{5}$$
$$E=mc^{2}$$
(\alpha+\beta\geq\frac12)
$$x = {-b \pm \sqrt{b^2-4ac} \over 2a}$$
(\alpha+\beta\geq\gamma) or $$\alpha+\beta\geq\gamma$$
[\alpha+\beta\geq\gamma] or $$!\alpha+\beta\geq\gamma$$
\begin{equation*} \begin{array}{rcl} p & = & \frac{1}{5}+\frac{2}{5}\times\left(\frac{1}{5}+\frac{2}{5}\times\left(\cdots\right)\right) \ & = & \frac{1}{5}\times\sum_{i=0}^\infty \left(\frac{2}{5}\right)^i \ & = & \frac{1}{5}\times\frac{1}{1-\frac{2}{5}} \ & = & \frac{1}{5}\times\frac{5}{3} \ & = & \frac{1}{3} \end{array} \end{equation*}
