Give a possible general term T(n) of a geometric sequence such that there are
9 terms between 1 and 7000 inclusive.
F5 Maths
2010-10-31 9:40 pm
回答 (1)
2010-11-01 12:06 am
✔ 最佳答案
T(1)=1T(2)=1*r^1
T(3)=1*r^2
.......
........
.......
.......
T(9)=1*r^(9-1)
T(9) < 7000
r^8 < 7000
8log r < log 7000
log r < (log 7000)/8
log r < 0.4806
r < 10^ (0.4806)
r< 3.024
r=3 (r is a integer)
therefore T(1) to T(9)
1, 3, 9, 27, 81, 243, 729, 2187, 6561
收錄日期: 2021-04-24 09:41:09
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20101031000051KK00527