推 SDUM:黎曼和,把 n^4 搬到 sigma 內即可! 140.120.149.5 04/13 12:36
→ skyword:會算了,不過還是想知道如何證明 219.84.1.83 04/13 13:05
推 TaiwanFlight:你要證明啥?210.240.176.170 04/13 13:07
→ skyword:比如說Σk^2是(n*n+1*2n+1)/6 219.84.218.188 04/13 15:25
推 TaiwanFlight:你舉的這個例子用歸納法即可210.240.176.170 04/13 18:29