Posted by haifeng on 2016-04-07 22:36:41 last update 2016-04-07 22:36:41 | Answers (0) | 收藏
对任意素数 $p$, 证明
\[ \biggl(\frac{2}{p}\biggr)=\begin{cases} 1, & \text{若}\ p\equiv\pm 1\pmod 8,\\ -1, & \text{若}\ p\equiv\pm 3\pmod 8. \end{cases} \]
