等差数列
中,公差
,
,其前
项和
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f3cb8d72bb2e281b943b3b430138ef7.png)
______________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5c1344592c925b273f2cb9b9e47ebbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef910998694cb9459c3795dd426208c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71151ff99f7d7877a0d9abc9c658b413.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f3cb8d72bb2e281b943b3b430138ef7.png)
更新时间:2020-04-17 20:34:42
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相似题推荐
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【推荐1】设等差数列
前
项和为
,若
,
,则
=__________
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.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/f89187b34512fa538137956cac5b3118.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a39dabf1d2cb4094bd2178576970d29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e35eeaabd951fb09b2926807da3685b.png)
您最近一年使用:0次
填空题-单空题
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较易
(0.85)
名校
【推荐2】已知数列
是公差不为零的等差数列,
,
,
成等比数列,第1,2项与第10,11项的和为68,则数列
的通项公式是________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e84c30444f13d37ada78285dc4f83b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
您最近一年使用:0次
填空题-单空题
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较易
(0.85)
解题方法
【推荐1】等差数列
中,
是前
项和,且
,
,则
的值为__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/277d63e2ebf03b22f9f110b436342043.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c8a2005f9b25260e2a530de3a22f79f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
您最近一年使用:0次
填空题-单空题
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解题方法
【推荐2】已知
是等差数列
的前
项和,且
,有下列四个命题:
①
;②
;③
;④数列
中的最大项为
.
其中正确命题的序号是________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e328b3fc0c8d8d349107b4e3dbd7776d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a425978da20cebf8c4c63953579e7b35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84f2d9ee270807691e37488f04772457.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85e6b37bbc762dafbf13a5c812e5f028.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7d7d4e54d452020c0afa8c2651c7647.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b14cf8ebb06ac6d8a92355e8c2bde519.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21987e8cb32af969efd72fdf0a805c5c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89fa4a4a5f9132f15f82edd02f0a9c99.png)
其中正确命题的序号是
您最近一年使用:0次