1.試用數學歸納法證明:對所有正整數n,
1.2+2.6+...+n(n+4)=【n(n+1)(2n+13)】/6
2a.試用數學歸納法證明:對所有正整數n,
1/(1.2)+1/(2.3)+1/(3.4)+...+1/(n(n+1))=n/(n+1)
b.由此,求使下列不等式成立的最小整數n
1/(1.2)+1/(2.3)+1/(3.4)+...+1/(n(n+1))≧9/10
3a. 試用數學歸納法證明:對所有正整數n,
1²+2²+3²+...n²=1/6n(n+1)(2+1))
b.由此證明
(n+1)²+(n+2)²+(n+3)²+...+(2n)²+1/6n(2n+1)(7n+1)
A math (3 條M.I)
2008-09-21 11:37 pm
回答 (1)
2008-09-22 2:13 am
收錄日期: 2021-04-23 20:43:16
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080921000051KK01591