數列及其極限
回答 (1)
2013-12-28 9:14 pm
✔ 最佳答案
1)an+1 = ⅕ (an) - 1
an+1 + 5/4 = ⅕ (an) + 1/4
an+1 + 5/4 = ⅕ (an + 5/4)
∴
an + 5/4 = (⅕)ⁿ⁻¹ (a1 + 5/4)
an + 5/4 = (⅕)ⁿ⁻¹ (2 + 5/4)
an = (⅕)ⁿ⁻¹ (13/4) - 5/4
2)
lim(n→∞) an
= lim(n→∞) (⅕)ⁿ⁻¹ (13/4) - 5/4
= 0(13/4) - 5/4
= - 5/4
收錄日期: 2021-04-21 22:29:42
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20131228000010KK00891