計算
n
Σ [k³ - (k - 1)³]
k=1
數學名義變數問題..
2008-09-23 5:40 pm
回答 (1)
2008-09-23 6:11 pm
✔ 最佳答案
Sum of (k -1)^3 from k = 1 to k = n is equivalent to sum of k^3 from k = 1 to k = (n-1). So their difference = n^3.2008-09-23 10:16:05 補充：
That is (1^3 + 2^3 + 3^3 +.......+ (n-1)^3 + n^3) - [ 0^3 + 1^3 + 2^3 + ......+ (n-1)^3] = n^3.
收錄日期: 2021-04-25 22:35:39
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080923000051KK00340