设
为等差数列
的前
项和,
,则
的公差为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53df3a56a7a3d273a4d8f87aaf89fd4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
A.1 | B.2 | C.3 | D.4 |
更新时间:2017-03-15 05:01:13
|
相似题推荐
单选题
|
适中
(0.65)
名校
解题方法
【推荐1】等差数列
满足
,
,记
,其中
表示不超过x的最大整数,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcb148bd8ad91c0ef275571029eee56d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3d08f31fde6cb6d7bc628709263770e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c4f5908d6a1217e493ed7586b6964dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4ec6a21eac7d45d6f925d45aa2055e5.png)
A.1000 | B.2445 | C.1893 | D.500500 |
您最近一年使用:0次
单选题
|
适中
(0.65)
【推荐2】我国古代数学名著《九章算术·均输》中记载了这样一个问题:“今有五人分五钱,令上二人所得与下三人等,问各得几何?”其意思为“已知甲、乙、丙、丁、戊五人分5钱,甲、乙两人所得与丙、丁、戊三人所得相同,且甲、乙、丙、丁、戊所得依次成等差数列,问五人各得多少钱?”(“钱”是古代一种重量单位).这个问题中,等差数列的通项公式为
A.![]() ![]() | B.![]() ![]() |
C.![]() ![]() | D.![]() ![]() |
您最近一年使用:0次
单选题
|
适中
(0.65)
解题方法
【推荐1】已知等差数列
的前
项和为
,且
,
;数列
满足
,则
取最大值时
的值为( )
![](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/23005bd2386f15812ce36833200d019d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5731f65834e58bb01c8d21a695e395ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/806173eff836cd68a2ff6f817a994423.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
A.5 | B.4 | C.3 | D.2 |
您最近一年使用:0次
单选题
|
适中
(0.65)
名校
【推荐2】已知
是公比不为1的等比数列
的前
项和,则“
成等差数列”是“存在不相等的正整数
,使得
成等差数列”的( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/089f16d8941a9a57c89a25d1f5fc1017.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/280860dd039e1305a5ccc455f63e8223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3ae138b4f85019d3faa39b271342adb.png)
A.充分不必要条件 | B.必要不充分条件 |
C.充要条件 | D.既不充分也不必要条件 |
您最近一年使用:0次