使用Markdown和Latex写数学公式

1. 美元符号排版

   $a+b=b+a$

   $a+b=b+a$

2. 上标

   $3x^2 - x + 2 = 0$

   $3x^2 - x + 2 = 0$

   $3x^{20} - x + 2 = 0$ //需要把20用括号括起来

   $3x^{20} - x + 2 = 0$

   $3x^{3x^{20} - x + 2 = 0} - x + 2 = 0$

   $3x^{3x^{20} - x + 2 = 0} - x + 2 = 0$ //将数学公式作为上标

3. 下标

   $a0,a1,a2$

   $a0,a1,a2$

   $a_0,a_1,a_2...,a_{100}$ //100需要括起来

   $a_0,a_1,a_2...,a_{100}$

4. 希腊字母

   $\alpha$ $\alpha$ $\Gamma$ $\Gamma$

   $\beta$ $\beta$ $\Delta$ $\Delta$

   $\gamma$ $\gamma$ $\Theta$ $\Theta$

   $\epsilon$ $\epsilon$

   $\pi$ $\pi$ $\Pi$ $\Pi$

   $\$omega$ $\omega$ $\Omega$ $\Omega$

   $\alpha^3 + \beta^2 + \gamma = 0$

   ​ $\alpha^3 + \beta^2 + \gamma = 0$

5. 数学函数

   $\log$ $\log$

   $\sin$ $\sin$

   $\cos$ $\cos$

   $\arcsin$ $\arcsin$

   $\arccos$ $\arccos$

   $\ln$ $\ln$

   $sin^2 x + \cos^2 x = 1$

   $sin^2 x + \cos^2 x = 1$

   $\y = \log_2 x$

   $y = \log_2 x$

   $\sqrt{2}$ $\sqrt{2}$

   $\sqrt{x^2 + y^2}$ $\sqrt{x^2 + y^2}$

   $\sqrt{2 + \sqrt{2}}$ $\sqrt{2 + \sqrt{2}}$`

   $\sqrt[4]{x}$ $\sqrt[4]{x}$

6. 分式

   $3/4$ $3/4$

   $\frac{3}{4}$ $\frac{3}{4}$

7. 乘法

   $1 \times 2 = 2$

   $1 \times 2 = 2$

   9 \div 3 = 3

   $9 \div 3 = 3$

8. 大括号

   $F^{HLLC}=\left\{ \begin{array}{rcl} F_L & & {0 < S_L}\\ F^*_L & & {S_L \leq 0 < S_M}\\ F^*_R & & {S_M \leq 0 < S_R}\\ F_R & & {S_R \leq 0} \end{array} \right.$

   $$ F^{HLLC}=\left\{
   \begin{array}{rcl}
   F_L       &      & {0      <      S_L}\\
   F^*_L     &      & {S_L \leq 0 < S_M}\\
   F^*_R     &      & {S_M \leq 0 < S_R}\\
   F_R       &      & {S_R \leq 0}
   \end{array} \right. $$
   

   $$ =\left\{
   \begin{array}{rcl}
   
   \end{array} \right. $$