1 . 在数列
中,
,
,且
(
),则
的值是__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/329785900390130a04a57d0b55aaa569.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f86a8746a583f411fb73c6334eb27b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/baa635d4ae41a0f7861d305b55bc618f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1933b7c3ace69622339353431c519b13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/133d021459e80aa19df293027610441e.png)
您最近一年使用:0次
2017-11-27更新
|
702次组卷
|
2卷引用:河南省豫北豫南名校2018届高三上学期精英联赛数学(理)试题
2014·江西宜春·一模
2 . 已知数列
满足
.
(1)若
成等比数列,求
的值.
(2)是否存在
,使数列
为等差数列?若存在,求出所有这样的
;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02c7245eb95ad3a7a8adc04494724c8b.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c14d9ae06f864498048d55088ff4e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
(2)是否存在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
您最近一年使用:0次