已知
为数列
的前
项和,
,且
.
(1)证明数列
是等差数列,并求其前
项和
;
(2)设数列
满足
,求证:
.
![](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/759caa9a3df7c8381f6600ed3143afdf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69c7266d90661cf4467f13c6f5eb670c.png)
(1)证明数列
![](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/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b7e7cd571c8cd141cbbfe5d0890bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5a28cd035abe6bbf35f7d2b50eb917b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/803608cc91af54afd734afadfd894245.png)
更新时间:2016-12-04 07:45:25
|
【知识点】 等差数列
相似题推荐
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】在①
,②
,③
三个条件中任选两个,补充到下面问题中,并解答.已知等差数列
的前
项和为
,满足: ,
.
(1)求
的最小值;
(2)设数列
的前
项和
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c687efc7a2166e3178bf54ff64e9f4b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bccd6b7cf0721f738ea046cd6399ca7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f788438009f5663030338b4c880d36b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.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/e145b6046bc80d0ffecc61ac67c87ca1.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdcaca9334dec86bfdbd0bbe8137b10b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c02e80983b88cdf6b540502816c87d13.png)
您最近一年使用:0次
【推荐2】在数列
中,
,且
.
(1)令
,证明:数列
为等差数列,并求数列
的通项公式;
(2)记数列
的前n项和为
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8323901a49cac29afd7d62864f088077.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbe8dd9af06e417ac8c1e6058ac7e7e6.png)
(1)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4188680e5320653753ad0340439cb77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)记数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75b0aac7da1b21e8b56c9d1ad67fb774.png)
您最近一年使用:0次