利用markdown语法，写出数学公式以及常用符号【持续更新！！！】

1.希腊字母

数学表达式	Markdown语法
α	\alpha
β	\beta
γ	\gamma
δ	\delta
ε	\epsilon
ζ	\zeta
η	\eta
θ	\theta
ι	\iota
κ	\kappa
λ	\lambda
μ	\mu
ν	\nu
ξ	\xi
ο	\omicron
π	\pi
ρ	\rho
σ	\sigma
τ	\tau
υ	\upsilon
φ	\phi
χ	\chi
ψ	\psi
ω	\omega

2.基本表达式

数学表达式	Markdow语法
x2	x^2
y?	y_1
∞	\infty
-∞	-\infty
a + b - c * d	a+b-c*d
a ÷ b	a\div{b}
a ± b	a\pm{b}
a/b	\frac{a}{b}
√b	\sqrt{b}
sinθ	\sin{\theta}
cosθ	\cos{\theta}
tanθ	\tan{\theta}
cotθ	\cot{\theta}
≦	\leq
≧	\geq

3.复杂表达式

（1）

\vec{F}
$$\vec{F}$$
(2)

\sum_{i=1}^{n}{a_i}
$$\sum _{i=1}^n{a}_i$$
(3)

\lim_{a\rightarrow+\infty}{a+b}
$$\underset{a\to +\infty }{\lim }a+b$$
(4)

\begin{matrix}
 1 & 2 & 3 \\
 4 & 5 & 6 \\
 7 & 8 & 9 
\end{matrix} 

$$\begin{array}{ccc}1& 2& 3\\ 4& 5& 6\\ 7& 8& 9\end{array}$$

(5)

 \left\{
 \begin{matrix}
   1 & 2 & 3 \\
   4 & 5 & 6 \\
   7 & 8 & 9
  \end{matrix}
  \right\} 

$$?\begin{array}{ccc}1& 2& 3\\ 4& 5& 6\\ 7& 8& 9\end{array}?$$

(6)

 \left[
 \begin{matrix}
   1 & 2 & 3 \\
   4 & 5 & 6 \\
   7 & 8 & 9
  \end{matrix}
  \right] 

$$\left[\begin{array}{ccc}1& 2& 3\\ 4& 5& 6\\ 7& 8& 9\end{array}\right]$$

(7)

 \left(
 \begin{matrix}
   1 & 2 & 3 \\
   4 & 5 & 6 \\
   7 & 8 & 9
  \end{matrix}
  \right) 

$$\left(\begin{array}{ccc}1& 2& 3\\ 4& 5& 6\\ 7& 8& 9\end{array}\right)$$

(8)

 \left\{
 \begin{matrix}
 1      & 2        & \cdots & 5        \\
 6      & 7        & \cdots & 10       \\
 \vdots & \vdots   & \ddots & \vdots   \\
 \alpha & \alpha+1 & \cdots & \alpha+4 
 \end{matrix}
 \right\}

$$?\begin{array}{cccc}1& 2& ?& 5\\ 6& 7& ?& 10\\ ?& ?& ?& ?\\ \alpha & \alpha +1& ?& \alpha +4\end{array}?$$

(9)

 \begin{vmatrix}
   1 & 2 & 3 \\
   4 & 5 & 6 \\
   7 & 8 & 9
  \end{vmatrix}

$$\left|\begin{array}{ccc}1& 2& 3\\ 4& 5& 6\\ 7& 8& 9\end{array}\right|$$

(10)

\begin{cases}
3x + 5y +  z \\
7x - 2y + 4z \\
-6x + 3y + 2z
\end{cases}

$$?\begin{array}{l}3x+5y+z\\ 7x?2y+4z\\ ?6x+3y+2z\end{array}$$

(11)

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

$$f(n)=\{\begin{array}{ll}n/2,& \text{if?}n\text{?is?even}\\ 3n+1,& \text{if?}n\text{?is?odd}\end{array}$$

4.复杂符号

（1）

\digamma
$$?$$
(2)

\Delta
$$\Delta$$
(3)

\Gamma
$$\Gamma$$
(4)

\beth
$$?$$
(5)

\daleth
$$?$$
(6)

\Xi
$$\Xi$$
(7)

\sqrt[n]{abc}
$$\sqrt[n]{abc}$$
(8)

\overline{abc}
$$\overline{abc}$$
(9)

\overleftarrow{abc}
$$\overleftarrow{abc}$$
(10)

\overbrace{abc}
$$\overbrace{abc}$$
(11)

\underbrace
$$\overbrace{abc}$$
(12)

\vert
$$|$$
(13)

\ |
$$\Vert$$
(14)

\langle
$$?$$
(15)

\rangle
$$?$$
(16)

\lfloor
$$?$$
(17)

\rfloor
$$?$$
(18)

\lceil
$$?$$
(19)

\rceil
$$?$$
(20)

\Uparrow
$$?$$
(21)

\uparrow
$$\uparrow$$
(22)

\Downarrow
$$?$$
(23)

\downarrow
$$\downarrow$$
(24)

\llcorner
$$└$$
(25)

\lrcorner
$$┘$$
(26)

\ulcorner
$$┌$$
(27)

\urcorner
$$┐$$
(28)

\sum
$$\sum$$
(29)

\prod
$$\prod$$
(30)

\coprod
$$?$$
(31)

\int
$$\int$$
(32)

\oint
$$\oint$$
(33)

\iint
$$?$$
(34)

\biguplus
$$?$$
(35)

\bigcap
$$?$$
(36)

\bigcup
$$?$$
(37)

\bigoplus
$$?$$
(38)

\bigotimes
$$?$$
(39)

\bigodot
$$?$$
(40)

\bigvee
$$?$$
(41)

\bigwedge
$$?$$
(42)

\bigsqcup
$$?$$

5.不常用符号

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我是韩一，用知识认识更多的人，欢迎大家指正！