已知等差数列
的前n项和为
,且
,则
( )
![](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/a612f917f74b81a0700bd8976e6094cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc4e70b360f988fdbd92300ab22c4613.png)
A.40 | B.45 | C.80 | D.90 |
更新时间:2022-07-12 21:54:07
|
相似题推荐
单选题
|
较易
(0.85)
解题方法
【推荐1】在等差数列
中,
,则前13项之和等于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29018b6dc815f9a566a93913ba1d6177.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
【推荐2】在等差数列
中,
,
,则
的前8项和为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febb4122ef4e047993a99582cc6ff35d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebeddc8c10d098573832edcb72d91f74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
A.3 | B.4 | C.5 | D.6 |
您最近一年使用:0次
单选题
|
较易
(0.85)
【推荐1】已知等差数列
中,
,
,则
的前
项和
的最小值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b499db552a74e4d609391271dcf72ad2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/936fde95cac375c0b3077d9d06748fcf.png)
![](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)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
单选题
|
较易
(0.85)
【推荐2】
是等差数列
的前
项和,若
,
,则使得
取得最大值的
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](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/a81974dea9c97235cfeba7551bc0e696.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c864fb2f798930481536e52374adc6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f3cb8d72bb2e281b943b3b430138ef7.png)
A.8 | B.7 | C.9 | D.10 |
您最近一年使用:0次