已知数列
的前
项和
,数列
的前
项和为
,且
.
(1)求数列
的通项公式;
(2)求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ab8159d658290b9df2453eef6f275b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a85bdd39825294ff236eb145e63623d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.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/3efa3ef366794b97bcd2356af4ba60fd.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
更新时间:2019-01-04 14:59:37
|
相似题推荐
解答题-问答题
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较易
(0.85)
名校
解题方法
【推荐1】已知数列
是公差为2的等差数列.
(1)若
成等比数列,求
的值;
(2)设
,数列
的前n项和为
.数列
满足
.记
,求数列
的最小项
(即
对任意
成立).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/920ad6b9e7f1c2c4a5a3025ba57e71b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ff6bd0b129ecb5c0ecfb3190a269ad0.png)
![](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/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9358ef249b920a98e761184e2cba45a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a9fb36a51456d5f5f061a3c10c3ccff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1db844dc31684da771e0a5dc2f5ece11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f203d39a87ac7a57a097abac7d6b5de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cea4ac187cbb465180e89f38250b3970.png)
您最近一年使用:0次
解答题-问答题
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较易
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【推荐2】已知无穷数列1×2,2×3,3×4,4×5,5×6,….
(1)求这个数列的第10项和第31项.
(2)420是不是这个数列中的项?如果是,求出其为第几项.
(1)求这个数列的第10项和第31项.
(2)420是不是这个数列中的项?如果是,求出其为第几项.
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
解题方法
【推荐1】已知等差数列
的前
项和为
,
.
(1)求数列
的通项公式;
(2)设
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.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/780e30a512a353d074686becce560ab0.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/216876de04325fd250c38c485cbc34b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次
【推荐2】设等比数列
的前n项和为
,已知
,且
成等差数列.
(1)求数列
的通项公式;
(2)设数列
满足
,求数列
的前n项和
.
![](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/4b79a42580dc46cb4ed5a14e09ab5e2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/581ad8b97c99c55d53ad3037cfa32319.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb0fd545a06ee3b88d251a08fd6ed66.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次