设
是数列
的前
项和,且
,
,则
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca4123422b5a6621da6a3214aa8c3e2a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/995b9bab96cdffba95f2aed5858d53ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04c2864e2ec3416cc4c081ac1f71a0af.png)
更新时间:2016-12-04 18:20:48
|
【知识点】 数列求和
相似题推荐
填空题-概念填空
|
较易
(0.85)
解题方法
【推荐1】完成下列表格:
递推关系 | 求法 | 名称 |
![]() | ![]() | 累加 |
![]() | ![]() | 累乘 |
![]() | ![]() | 取倒数 |
![]() | ![]() | 构造法 |
![]() | 利用![]() | 转化法 |
您最近一年使用:0次
填空题-单空题
|
较易
(0.85)
【推荐2】已知数列
的通项公式
,
,其前
项和为
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d238a52feae87b0778ba324dc144d50.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec1535d1cc7d0d713427bed280c1f608.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cea4ac187cbb465180e89f38250b3970.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/0d238a52feae87b0778ba324dc144d50.png)
您最近一年使用:0次