一个真切的问题

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科学公式 TeX(KaTeX)

行内的公式

多行公式：

\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)

\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} }
        }
    }

f(x) = \int_{-\infty}^\infty
    \hat f(\xi)\,e^{2 \pi i \xi x}
    \,d\xi

分页符 Page break

Print Test: Ctrl + P

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绘制流程图 Flowchart

st=>start: 用户登陆
op=>operation: 登陆操作
cond=>condition: 登陆成功 Yes or No?
e=>end: 进入后台

st->op->cond
cond(yes)->e
cond(no)->op

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绘制序列图 Sequence Diagram

Andrew->China: Says Hello
Note right of China: China thinks\nabout it
China-->Andrew: How are you?
Andrew->>China: I am good thanks!