Posted by haifeng on 2012-06-07 20:42:23 last update 2012-06-07 20:42:23 | Answers (1) | 收藏
即证明
\[[na]=[a]+[a+\frac{1}{n}]+[a+\frac{2}{n}]+\cdots+[a+\frac{n-1}{n}]\]
