數學知識交流---整數部份(3)
回答 (1)
2011-06-03 4:25 am
✔ 最佳答案
Solve: n^3 + n^2 + n^1 + n^0 = 1000n^2 (n+1) + n^0 (n+1) = 1000
(n^2 + 1) (n+1) = 1000
Let (n^2 + 1) (n+1) = a
When the value of n increases, the value of a will also increase.
When n = 10
101×11 = 1111
a = 1111 > 1000
so n<10
When n = 9
82×10 = 820
a = 820 < 1000
so n>9
so 9<n<10
so the 整數部分 of n is 9.
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原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110602000051KK00807