Posted by haifeng on 2023-08-23 23:19:47 last update 2023-08-23 23:41:37 | Answers (0) | 收藏
求 $\sin\frac{\pi}{5}$ 的值.
\[ \sin^2\frac{\pi}{5}=\frac{5-\sqrt{5}}{8} \]
