Hello World公式测试

$$E=mc^2$$

$$mv=mv_1 + mv_2$$

$$\frac{1}{2} m v_1^2 + \frac{1}{2} m v_2^2 = \frac{1}{2} m v^2$$

$$\begin{Bmatrix} a & b \\ c & d \end{Bmatrix}$$

$$\frac{a}{b}$$

$$x = \begin{cases} a &\text{if } b \\ c &\text{if } d \end{cases}$$

$$\begin{cases} mv=mv_1 + mv_2 \\ \frac{1}{2} m v_1^2 + \frac{1}{2} m v_2^2 = \frac{1}{2} m v^2 \end{cases}$$