已知正项数列
满足:
,其前
项和为
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fe56d5d32d3f11e0b1c8bcabddba404.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/848464628360a61d2659595686676ea6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fe56d5d32d3f11e0b1c8bcabddba404.png)
更新时间:2020-04-06 14:56:20
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【知识点】 裂项相消法求和
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名校
解题方法
【推荐1】在数列{an}中,
,若
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,则项数n=________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de85a69e4af66d860c569e3cd5c741df.png)
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您最近一年使用:0次
填空题-单空题
|
较易
(0.85)
解题方法
【推荐2】已知
的前
项和
,数列
的前5项和![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13e7dbf7f4fc25d3a971cb14b8c22170.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c133f850a40f4d23c30fa91a1e7d74a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4300dca231e2f4b37f70900b33439d5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adf19c8d1c1721dbf61b48b62fe6840d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13e7dbf7f4fc25d3a971cb14b8c22170.png)
您最近一年使用:0次