Latex常见用法

官方tutorial：
https://math.meta.stackexchange.com/questions/5020/mathjax-basic-tutorial-and-quick-reference
（用于自己学习整理）

1.Greek letters

code	letter
\alpha	$\alpha$
\beta	$\beta$
\omega	$\omega$
\Gamma	$\Gamma$
\Delta	$\Delta$
Omega	$\Omega$

2.上下标 superscripts&subscripts

上标	^
下标	_

e.g.
x_i^2………… $x_i^2$
{x_i}^2 …….. ${x_i}^2$

3.分数

\frac ab	$\frac ab$
\frac {\sqrt x} {a+1}	$\frac{\sqrt x}{a+1}$
{a+1 \over b+1}	${a+1\over b+1}$

4.求和符号

\sum_1^n	$\sum_1^n$
\sum_{i=0}^\infty i^2	$\sum_{i=0}^\infty i^2$

5.积分符号

\int_0^1 x^2

\int_{0}^{1} x^{2}

$\int_0^1 x^2$

6.根号

\sqrt {x^3}	$\sqrt {x^3}$
\sqrt [3] {x+3}	$\sqrt [3] {x+3}$

7.极限

\lim\limits_{x\to 0}

lim_{x \to 0}

$\lim\limits_{x\to 0}$

8.不等符号

\lt	\gt	\le	\ge	\neq	\not\lt
$\lt$	$\gt$	$\le$	$\ge$	$\neq$	$\not\lt$

9.特殊符号

\subset	\subseteq	\supset	\supseteq	\in	\notin
$\subset$	$\subseteq$	$\supset$	$\supseteq$	$\in$	$\notin$

\to	\leftarrow	\Rightarrow
$\to$	$\leftarrow$	$\Rightarrow$

10.其他符号

\cdot(点乘)	\pm	\mp
$\cdot$	$\pm$	$\mp$

11.方程组

Code01：

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

\\………分隔每个方程
&………在这里相当于Tab键
$\\[2ex]$
显示：

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

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

Code02:

$$
\left\{ 
\begin{aligned}
a_1x+b_1y+c_1z&=d_1 \\ 
b_2y+c_2z&=d_2 \\ 
a_2x+b_3y+c_3z&=d_3
\end{aligned}
\right.
$$

显示：

{\begin{aligned} a_{1} x + b_{1} y + c_{1} z & = d_{1} \\ b_{2} y + c_{2} z & = d_{2} \\ a_{2} x + b_{3} y + c_{3} z & = d_{3} \end{aligned}

$\left\{ \begin{aligned} a_1x+b_1y+c_1z&=d_1 \\ b_2y+c_2z&=d_2 \\ a_2x+b_3y+c_3z&=d_3 \end{aligned} \right.$

Code03:

$$\begin{aligned}
a &= b + c \\
  &= d + e + f + g \\
  &= h + i
\end{aligned}\tag{2}$$

显示：

\begin{matrix} (2) & \begin{aligned} a & = b + c \\ = d + e + f + g \\ = h + i \end{aligned} \end{matrix}

$\begin{aligned} a &= b + c \\ &= d + e + f + g \\ &= h + i \end{aligned}\tag{2}$

Code04:

$$\begin{align}
a &= b + c \tag{3} \\
x &= yz \tag{4}\\
l &= m - n \tag{5}
\end{align}$$

显示：

\begin{aligned} (3) & a & = b + c \\ (4) & x & = y z \\ (5) & l & = m - n \end{aligned}

$\begin{align} a &= b + c \tag{3} \\ x &= yz \tag{4}\\ l &= m - n \tag{5} \end{align}$

Code05:

\begin{alignat}{5}
  \max \quad        & z = &   x_1  & + & 12 x_2  &   &       &         && \\
  \mbox{s.t.} \quad &     & 13 x_1 & + & x_2     & + & 12x_3 & \geq 5  && \tag{constraint 1} \\
                    &     & x_1    &   &         & + & x_3   & \leq 16 && \tag{constraint 2} \\
                    &     & 15 x_1 & + & 201 x_2 &   &       & =    14 && \tag{constraint 3} \\
                    &     & \rlap{x_i \ge 0, i = 1, 2, 3}
\end{alignat}

显示：

\begin{aligned} (3) & max & z = & x_{1} & + & 12 x_{2} \\ (constraint 1) & s.t. & 13 x_{1} & + & x_{2} & + & 12 x_{3} & \geq 5 \\ (constraint 2) & x_{1} & + & x_{3} & \leq 16 \\ (constraint 3) & 15 x_{1} & + & 201 x_{2} & = 14 \\ (4) & x_{i} \geq 0, i = 1, 2, 3 \end{aligned}

$\begin{alignat}{5} \max \quad & z = & x_1 & + & 12 x_2 & & & && \\ \mbox{s.t.} \quad & & 13 x_1 & + & x_2 & + & 12x_3 & \geq 5 && \tag{constraint 1} \\ & & x_1 & & & + & x_3 & \leq 16 && \tag{constraint 2} \\ & & 15 x_1 & + & 201 x_2 & & & = 14 && \tag{constraint 3} \\ & & \rlap{x_i \ge 0, i = 1, 2, 3} \end{alignat}$

12.表格

Code：

$$
\begin{array}{c|lcr}
n & \text{Left} & \text{Center} & \text{Right} \\
\hline
1 & 0.24 & 1 & 125 \\
2 & -1 & 189 & -8 \\
3 & -20 & 2000 & 1+10i
\end{array}
$$

{c|lcr}………表示每一列对齐方式c(中心)lr（左右）|（分割线）
$\\[2ex]$
显示：

\begin{array}{clcr} n & Left & Center & Right \\ 1 & 0.24 & 1 & 125 \\ 2 & - 1 & 189 & - 8 \\ 3 & - 20 & 2000 & 1 + 10 i \end{array}

$\begin{array}{c|lcr} n & \text{Left} & \text{Center} & \text{Right} \\ \hline 1 & 0.24 & 1 & 125 \\ 2 & -1 & 189 & -8 \\ 3 & -20 & 2000 & 1+10i \end{array}$

13.文字

Code:

$\color{silver}{yourtext}$
$\color{#f00}{yourtext}$

显示：
$\color{silver}{yourtext}$
$\color{#f00}{yourtext}$

about颜色：

color
color2

14.关系图