1 . 数列
的通项公式为
,其前
项和为
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bca8f26c7e2cf5c7c4eaf39b089ae52.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2eac2e444fa6af3cff7e42dd592f475.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/7bca8f26c7e2cf5c7c4eaf39b089ae52.png)
您最近一年使用:0次
2022-01-14更新
|
944次组卷
|
4卷引用:天津市宝坻区第四中学2022-2023学年高二上学期期末模拟数学试题
2 . 已知数列
是公差不为0的等差数列,且
,则数列
的前2021项和为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14ab4a389aa3d8fed4919525958c9e50.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
A.![]() | B.![]() | C.2021 | D.4042 |
您最近一年使用:0次