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[数列] 数列通项公式

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xianjian Posted 2017-4-17 16:45 |Read mode
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kuing Posted 2017-4-17 17:01
\begin{gather*}
2a_{n}=(n+1)(-1+a_{n+1}-a_{n}) \\
a_{n+1}=\frac{n+3}{n+1}a_{n}+1 \\
\frac{a_{n+1}}{(n+3)(n+2)}=\frac{a_{n}}{(n+2)(n+1)}+\frac{1}{(n+3)(n+2)} \\
\frac{a_{n+1}}{(n+3)(n+2)}+\frac{1}{n+3}=\frac{a_{n}}{(n+2)(n+1)}+\frac{1}{n+2}
\end{gather*}

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 Author| xianjian Posted 2017-4-17 18:19
谢谢kuing,谢谢!!!

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 Author| xianjian Posted 2017-4-17 18:37
回复 2# kuing

新课标卷最近这几年数列考得都不难,主要考查基本知识、技能的运用,在复习备考中大多只是注重基本的东西。
请教kuing老师,像这种题目涉及的变化技能需要加强嘛?谢谢!
这题是云南省二统的题目。

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kuing Posted 2017-4-17 19:29
回复 4# xianjian

又要强调:我不是老师。
我只思考题目怎么解怎么写,其余不理。

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