test
test math formula: $$\int_0^\infty\frac{1}{1+x^2}dx=\pi/2$$
$\alpha\lt\beta$，$\gamma\pi$
$$\frac{\sin(x)}{\cos(x)}$$
[https://haokan.baidu.com/v?pd=wisenatural&vid=14834730717404488356]
test math formula: $$\int_0^\infty\frac{1}{1+x^2}dx=\pi/2$$
$\alpha\lt\beta$，$\gamma\pi$
$$\frac{\sin(x)}{\cos(x)}$$
[https://haokan.baidu.com/v?pd=wisenatural&vid=14834730717404488356]