我響網上面見到Geometric Sequence既general term係an= a1rn-1
我想問D a&n&r係乜??
係咪每一題既a,n,r刀一樣??
請問中文問!
假如1,3,9,27,81,...
咁請general term係咩?
Geometric Sequence !!!
2008-08-08 12:58 am
回答 (1)
2008-08-08 1:54 am
✔ 最佳答案
a=首項n=項數
r=公比
設一Geometric Sequence,想找第5項
1,2,4,8,........
a=1
n=5
r=2[1*2=2,2*2=4,4*2=8]
a5=1(2)^(5-1)=16
1,3,9,27,81,...
3^0=1
3^1=1
3^2=9
3^3=27
general term=3^(n-1)
收錄日期: 2021-04-22 00:36:05
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080807000051KK02095