1 . 已知
,若
成等差数列且公差不为零,求证:
不可能成等差数列.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a521891098b625f372ff648d110afe1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f81b8a02e231884bc36fdc4870830cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
您最近一年使用:0次
名校
2 . 已知
,
均为等差数列,且
,
,
,则数列
的前5项和为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e8c45e4c4ab30665338dd87a2258f23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87ea014220aa658c8baa6e1f43e686a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1793fecd8551ee9cd7b71e4c7c6a00e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5344eadd4711db34e3f935aedd5fb270.png)
A.35 | B.40 | C.45 | D.50 |
您最近一年使用:0次
2023-02-23更新
|
520次组卷
|
6卷引用:青海省西宁市2023届高三二模理科数学试题
解题方法
3 . 记等差数列
的前
项和为
,若
,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/4bdf39c8328e9526402ff09fdc604987.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdfe37d536c2f83b8da9810fd410f82e.png)
A.4 | B.8 | C.12 | D.16 |
您最近一年使用:0次
2023-01-29更新
|
1582次组卷
|
4卷引用:青海省玉树州2023届高三第三次联考数学文科试题