Latex 公式

$$a \equiv b$$

$$a \bmod b$$

$$a \cdot b$$

$$0 \neq 1 \quad 1 \equiv 9 \quad (\bmod 2)$$

$$a^2 + b^2 = c^2$$
$$C_a^b = C_{a \bmod p}^{b \bmod p} \cdot C_{a / p} ^{b / p}$$

$$\sqrt{x^2} + \sqrt{x^2 + \sqrt{y}} = \sqrt[3]{k_i} - \frac{x}{m}$$

$$\overline{a + b} \qquad \underline{a - b}$$

$$\vec{a} + \overrightarrow{AB} = \overleftarrow{DE}$$

$$\overbrace{a + 2 + 3 + \cdots + n}^{n} = \underbrace{a + b + \cdots + z}_{26}$$

$$\lim_{x \to \infty}x^2_{22} - \int_1^5 x\mathrm{d}x + \sum_{n = 1}^{20}n^2 = \prod_{j = 1}^3y_i + \lim_{x \to -2} \frac{x - 2}{x}$$

$$\hat{x} \\qquad \bar{x} \qquad \tilde{x}$$

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