It is about Laws of integral indices..
Question:
3^n+1 - 3^n-1 / 2× 3^n
Thank you very much if you solve this question!!
F.3 Mathematics...
2010-09-08 1:52 am
回答 (1)
2010-09-08 2:00 am
✔ 最佳答案
[3^(n+1) - 3^(n-1)] / [2(3^n)]= (3^n) (3 - 3^-1) / [2(3^n)]
= (3 - 3^-1) / 2
= (3 - 1/3) / 2
= (2/3)/2
= 1/3
2010-09-07 18:16:33 補充：
Corrections :
[3^(n+1) - 3^(n-1)] / [2(3^n)]
= (3^n) (3 - 3^-1) / [2(3^n)]
= (3 - 3^-1) / 2
= (3 - 1/3) / 2
= (9/3 - 1/3) / 2
= (8/3) / 2
= 4/3
Sorry!!
收錄日期: 2021-04-21 22:15:36
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100907000051KK00895