在正项等差数列
中,
,且
,
,
成等比数列.
(1)求数列
的通项公式及前n项和
;
(2)记
,求数列
的前n项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/614206299653e4111ac285f5375e34c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7f8757834ec1c975d31b371c5c65655.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18a844d9cb42e2d7c8d5d951ce33ac97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
更新时间:2022-01-29 13:49:48
|
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解答题-问答题
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适中
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【推荐1】已知等比数列
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解答题-证明题
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适中
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解题方法
【推荐2】已知等差数列
的公差为
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(1)求数列
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(2)令
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f40c9b7ce7a2145770649e30cb222a43.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0cd94760672596ab76e5962b372485a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0eac8e06fcc400177c6cbaad57ff6ea.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe229b24e2d56ff6b491725ceae4ff2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bee4464b3b4eb6e52ee02f095aae84f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bedbe3d8fa49e6af56cddc80870d92cd.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7035f77c73ceda74a470586b8f86c21.png)
(Ⅰ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe229b24e2d56ff6b491725ceae4ff2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b708c8dcb2d66eb2ce0b3718a9cd924a.png)
(Ⅱ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07878c8ccaec5fe5c62cb6739d8f46f8.png)
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(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b52c9237cb0b4acc568d4afb12997186.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次
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适中
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名校
解题方法
【推荐1】已知数列
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