x=\frac{-b±\sqrt{{b}^{2}-4ac}}{2a}\text{.}
\begin{array}{rl}\stackrel{˙}{x}& =\sigma \left(y-x\right)\\ \stackrel{˙}{y}& =\rho x-y-xz\\ \stackrel{˙}{z}& =-\beta z+xy\end{array}
{\left(\sum _{k=1}^{n}{a}_{k}{b}_{k}\right)}^{2}\le \left(\sum _{k=1}^{n}{a}_{k}^{2}\right)\left(\sum _{k=1}^{n}{b}_{k}^{2}\right)
{\mathbf{V}}_{1}×{\mathbf{V}}_{2}=|\begin{array}{ccc}\mathbf{i}& \mathbf{j}& \mathbf{k}\\ \frac{\mathrm{\partial }X}{\mathrm{\partial }u}& \frac{\mathrm{\partial }Y}{\mathrm{\partial }u}& 0\\ \frac{\mathrm{\partial }X}{\mathrm{\partial }v}& \frac{\mathrm{\partial }Y}{\mathrm{\partial }v}& 0\end{array}|
P\left(E\right)=\left(\genfrac{}{}{0}{}{n}{k}\right){p}^{k}{\left(1-p\right)}^{n-k}
\frac{1}{\left(\sqrt{\varphi \sqrt{5}}-\varphi \right){e}^{\frac{2}{5}\pi }}=1+\frac{{e}^{-2\pi }}{1+\frac{{e}^{-4\pi }}{1+\frac{{e}^{-6\pi }}{1+\frac{{e}^{-8\pi }}{1+\dots }}}}
1+\frac{{q}^{2}}{\left(1-q\right)}+\frac{{q}^{6}}{\left(1-q\right)\left(1-{q}^{2}\right)}+\cdots =\prod _{j=0}^{\mathrm{\infty }}\frac{1}{\left(1-{q}^{5j+2}\right)\left(1-{q}^{5j+3}\right)},\text{for }|q|<1.
\begin{array}{rl}\mathrm{\nabla }×\stackrel{\to }{\mathbf{B}}-\frac{1}{c}\frac{\mathrm{\partial }\stackrel{\to }{\mathbf{E}}}{\mathrm{\partial }t}& =\frac{4\pi }{c}\stackrel{\to }{\mathbf{j}}\\ \mathrm{\nabla }\cdot \stackrel{\to }{\mathbf{E}}& =4\pi \rho \\ \mathrm{\nabla }×\stackrel{\to }{\mathbf{E}}+\frac{1}{c}\frac{\mathrm{\partial }\stackrel{\to }{\mathbf{B}}}{\mathrm{\partial }t}& =\stackrel{\to }{\mathbf{0}}\\ \mathrm{\nabla }\cdot \stackrel{\to }{\mathbf{B}}& =0\end{array}