等比數列512,256,128 求最小整數項?
回答 (2)
2007-05-09 7:20 pm
✔ 最佳答案
等比數列512,256,128 求最小整數項通項 T(n) = ar^(n-1)
首項 = 512
r = (1/2)
512(1/2)^(n-1) => 1
(1/2)^(n-1) => 1/512
1/2^(n-1) => 1 / 2^9
n-1 => 9
n = > 10
n = 10
當n = 10
T(10) = 512(1/2)^(10-1) = 1
最小整數項 = 1
2007-05-10 5:36 am
you can know the answer is 1 directly
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https://hk.answers.yahoo.com/question/index?qid=20070509000051KK00771