When using Typora, I often forget some LaTeX syntax, so I'm recording it here for future reference.

Special Usage

Braces

Effect:

Q1(x)+Q2(x)+Qe(x)⏞上括号=mQ1(x)+Q2(x)+Qe(x)⏟下括号=n\begin{align} \overbrace{Q_1(x) + Q_2(x)+Q_e(x)}^{上括号} = m \\ \underbrace{Q_1(x) + Q_2(x)+Q_e(x)}_{下括号}=n \end{align}

Code:

\overbrace{Q_1(x) + Q_2(x)+Q_e(x)}^{上括号} = m
\underbrace{Q_1(x) + Q_2(x)+Q_e(x)}_{下括号} = n

argmin

Effect:

3

Syntax:

\underset{x\in S}{{\arg\max} \, f(x)} = \{x \in S: \, f(x) = \max_{y \in S} f(y)\}

Long Equals Sign

Effect:

lim⁡x→0x2−sin⁡2xx4=L′Hospitallim⁡x→02x−sin⁡2x4x3\begin{align} &\lim_{x\rightarrow0}\frac{x^2-\sin^2x}{x^4}\\ \xlongequal{L'Hospital}\lim_{x\rightarrow0}&\frac{2x-\sin2x}{4x^3}\\ \end{align}

Syntax:

\begin{align}
&\lim_{x\rightarrow0}\frac{x^2-\sin^2x}{x^4}\\
\xlongequal{L'Hospital}\lim_{x\rightarrow0}&\frac{2x-\sin2x}{4x^3}\\
\end{align}

Matrix

Effect 1:

3

Syntax:

a = \left[
\begin{matrix}
	\alpha_1 & test1\\
	\alpha_2 & test2\\
	\alpha_3 & test3
\end{matrix}
\right]

Effect 2:

3
\left\{
 \begin{matrix}
 1      & 2        & \cdots & 5        \\
 6      & 7        & \cdots & 10       \\
 \vdots & \vdots   & \ddots & \vdots   \\
 \alpha & \alpha+1 & \cdots & \alpha+4 
 \end{matrix}
 \right\}

Truth Table

Effect:

3

Syntax:

\begin{array}{cc|c}
A&B&F\\
\hline 0&0&0\\
0&1&1\\
1&0&1\\
1&1&1\\
\end{array}

LaTeX Symbols

3333