1 . 设数列
的前
项和为
,
,
,则( )
![](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/eba83359167d8ca8c9eafa8a23f34a92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7acac0a395f2315fdfe7014548dbc033.png)
A.![]() | B.![]() |
C.对任意的![]() ![]() | D.对任意的![]() ![]() |
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名校
解题方法
2 . 数列
满足
,则数列
的前100项和为__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3458a17fd8540a519aa4a14725f9bd27.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
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13-14高一下·重庆·阶段练习
3 . 将一个等差数列依次写成下表:
第1行:2
第2行:5 8 11
第3行:14 17 20 23 26
………………………………………………
第
行:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30e843a95617ad24ea4e789a0cdc5912.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68c82be573157fd2c8068cb000505b43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aec8aa05d77a638e99494af9dfc0896.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/907e338a2cd8381353173126753e2415.png)
………………![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2814549b2e9f30007ab2d811dd9adf9.png)
(其中
表示第
行中的第
个数)
那么第
行的数的和是_________________ .
第1行:2
第2行:5 8 11
第3行:14 17 20 23 26
………………………………………………
第
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30e843a95617ad24ea4e789a0cdc5912.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68c82be573157fd2c8068cb000505b43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aec8aa05d77a638e99494af9dfc0896.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/907e338a2cd8381353173126753e2415.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/392546a6637cb8faf9f356f4739cd7e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2814549b2e9f30007ab2d811dd9adf9.png)
(其中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee641d39bc70aa40e611fcfc6b78f30b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c05b9832b09731a574d4a4adf7448de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7600d2cfbdc6146db96cc545706004f6.png)
那么第
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
您最近一年使用:0次