1 . 已知数列
中,
,数列
满足:
.
(1)求证:数列
是等差数列,并求数列
的通项公式;
(2)求
的值;
(3)求数列
中的最大项和最小项,并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d61054cd9251ae9646d3dcbcf41efa28.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19aec23982fb581ab92aa0dc4e254cad.png)
(1)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/185e26413d7faabfaf59114fe16c7b80.png)
(3)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
您最近一年使用:0次
2 . 设正项数列
的前
项和为
,首项为1,数列
是公差为
(
且
)的等差数列.
(1)求数列
的通项公式;
(2)求证:数列
是递增数列;
(3)是否存在正常数
,使得
为等差数列?若存在,求出
的值和此时
的取值范围;若不存在,说明理由.
![](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/1e29dd8ef4f5520e496c7d0641228802.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ef72a71993e2ac3c933e38e28af3eaa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f71acdb04454c77e1e25ad4f336cccfe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45482d31d1d7448c9f3922b4d2a55331.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cce224c28ca451c4f105dc3b077736cb.png)
(2)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcef103f9b75b511a1450f4884368730.png)
(3)是否存在正常数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f717a63948b6e2030335fdd1a9e55cc0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
您最近一年使用:0次
2020-10-17更新
|
454次组卷
|
3卷引用:第5课时 课后 等比数列的前n项和