1 . 已知数列{an}满足,an+2=3an+1﹣2an,a1=1,a2=3,记bn
,Sn为数列{bn}的前n项和.
(1)求证:{an+1﹣an}为等比数列,并求an;
(2)求证:Sn
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3f36a36bd6ad6b5eb0c73dcbd56352f.png)
(1)求证:{an+1﹣an}为等比数列,并求an;
(2)求证:Sn
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a56b6cc13dd13b05f14435fce6ad3f2.png)
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2 . 对于正整数
与实数
,
,…,
,记
.
(1)若
,
求,
的取值范围;
(2)当
时,判断:是否存在实数
,
,…,
,使得
成立.若存在,请求出任意一组
,
,…,
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f35f7dcce39f3d4dc6b7faf84dc1d0a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d59f78142739f199e48e0b6ab19fc46.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16c8d0474f7d81ef8dbefaacfd5afe7c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86288a7076fa0a46eaef6e54698b031e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bffc9c4bf9de4d804885955aff039ca.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bcca0e992d47f3db0be185ba861adf0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f35f7dcce39f3d4dc6b7faf84dc1d0a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1a50f815f27b1c935fe28935cb2d3ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08d69a97da82861896359caae5d0d7d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f35f7dcce39f3d4dc6b7faf84dc1d0a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1a50f815f27b1c935fe28935cb2d3ff.png)
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