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[数列] 一道数列小题

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aishuxue Posted 2019-3-11 15:11 |Read mode

已知$a_{n+1}^2-a_{n+1}=a_n^2-1$, 且$S_{13}=a_{13}^2$,求$a_1$的所有可能值.

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游客 Posted 2019-3-11 15:20

4或-3

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Author| aishuxue Posted 2019-3-11 15:25

求分析过程

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kuing Posted 2019-3-11 15:30

这么简单，`a_{n+1}=a_{n+1}^2-a_n^2+1` 然后求和啊

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Author| aishuxue Posted 2019-3-11 15:33

谢谢。

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敬畏数学 Posted 2019-3-13 11:44

难度低于此贴。forum.php?mod=viewthread&tid=5736

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