\[E=mc^2\]
Inline 行内的公式 $$E=mc^2$$ 行内的公式，行内的$$E=mc^2$$公式。
$$c = \pm\sqrt{a^2 + b^2}$$
$$x > y$$
$$f(x) = x^2$$
$$\alpha = \sqrt{1-e^2}$$
$$(\sqrt{3x-1}+(1+x)^2)$$
$$\sin(\alpha)^{\theta}=\sum_{i=0}^{n}(x^i + \cos(f))$$
$$\dfrac{-b \pm\sqrt{b^2 - 4ac}}{2a}$$
$$f(x) = \int_{-\infty}^\infty\hat f(\xi)\,e^{2 \pi i \xi x}\,d\xi$$
$$\displaystyle \frac{1}{\Bigl(\sqrt{\phi \sqrt{5}}-\phi\Bigr) e^{\frac25 \pi}} = 1+\frac{e^{-2\pi}} {1+\frac{e^{-4\pi}} {1+\frac{e^{-6\pi}} {1+\frac{e^{-8\pi}} {1+\cdots} } } }$$
$$\displaystyle \left( \sum\_{k=1}^n a\_k b\_k \right)^2 \leq \left( \sum\_{k=1}^n a\_k^2 \right) \left( \sum\_{k=1}^n b\_k^2 \right)$$
$$a^2$$
$$a^{2+2}$$
$$a_2$$
$${x_2}^3$$
$$x_2^3$$
$$10^{10^{8}}$$
$$a_{i,j}$$
$$_nP_k$$
$$c = \pm\sqrt{a^2 + b^2}$$
$$\frac{1}{2}=0.5$$
$$\dfrac{k}{k-1} = 0.5$$
$$\dbinom{n}{k} \binom{n}{k}$$
$$\oint_C x^3\, dx + 4y^2\, dy$$
$$\bigcap_1^n p \bigcup_1^k p$$
$$e^{i \pi} + 1 = 0$$
$$\left ( \frac{1}{2} \right )$$
$$x_{1,2}=\frac{-b\pm\sqrt{\color{Red}b^2-4ac}}{2a}$$
$${\color{Blue}x^2}+{\color{YellowOrange}2x}-{\color{OliveGreen}1}$$
$$\textstyle \sum_{k=1}^N k^2$$
$$\dfrac{ \tfrac{1}{2}[1-(\tfrac{1}{2})^n] }{ 1-\tfrac{1}{2} } = s_n$$
$$\binom{n}{k}$$
$$0+1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+\cdots$$
$$\sum_{k=1}^N k^2$$
$$\textstyle \sum_{k=1}^N k^2$$
$$\prod_{i=1}^N x_i$$
$$\textstyle \prod_{i=1}^N x_i$$
$$\coprod_{i=1}^N x_i$$
$$\textstyle \coprod_{i=1}^N x_i$$
$$\int_{1}^{3}\frac{e^3/x}{x^2}\, dx$$
$$\int_C x^3\, dx + 4y^2\, dy$$
$${}_1^2\!\Omega_3^4$$