在①
,②
,③
这三个条件中任选一个,补充在下面的问题中,并解答.
问题:设
是数列
的前
项和,且
,______,求
的通项公式,并判断
是否存在最大值,若存在,求出最大值;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ecb9d4582849f81fe946584a764b50a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13df6bc46e9b0b796343178fa18295b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9995dbae52770a9aeceac87590a4b53b.png)
问题:设
![](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/86fc336b4a83bf6d66c4afcc431597f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
更新时间:2020-11-28 09:05:50
|
相似题推荐
【推荐1】已知数列
满足
,
.
(1)求数列
的通项公式;
(2)
为数列
的前n项和,求证:
.
![](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/860785a9e71406ce5c7fab3dac365512.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba57c83d526ac308d1461e80fcca9f36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74bb18c7b30c44d3746af91094705c50.png)
您最近一年使用:0次
【推荐2】列三角形数表
![](https://img.xkw.com/dksih/QBM/2021/7/13/2763481566658560/2777724325470208/STEM/d4943adf-9d35-4ddb-8d25-f1ac7c95aec4.png?resizew=348)
假设第
行的第二个数为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ff13d941d09175aad24d1b14aeaddf1.png)
(1)归纳出
与
的关系式并求出
的通项公式;
(2)求证:数列
中任意的连续三项不可能构成等差数列.
![](https://img.xkw.com/dksih/QBM/2021/7/13/2763481566658560/2777724325470208/STEM/d4943adf-9d35-4ddb-8d25-f1ac7c95aec4.png?resizew=348)
假设第
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ff13d941d09175aad24d1b14aeaddf1.png)
(1)归纳出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/090426eb29836bc30c006b3739c08057.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
(2)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2ab8426339cd9c1b56a5badf342172b.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐1】在正项等比数列
中,公比
,且
,
.
(1)求数列
的通项公式;
(2)设
,数列
的前
项和为
,当
取最大值时,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fecd48d65ac4f8197c45231f68e8bce1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb334e165679c6cb500c994cffa47147.png)
![](https://img.xkw.com/dksih/QBM/2018/1/23/1866727648108544/1867888016941056/STEM/0b411bcfd9c443ae93b4576226974ccf.png?resizew=160)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0f6000421c5370e4b89f23be199f388.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://img.xkw.com/dksih/QBM/2018/1/23/1866727648108544/1867888016941056/STEM/b12c0d80bef44c5b914d545bd3c71b9c.png?resizew=120)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】已知数列{an}是一个等差数列,且a2=1,a5=-5.
(1)求{an}的通项an;
(2)求{an}前n项和Sn的最大值.
(1)求{an}的通项an;
(2)求{an}前n项和Sn的最大值.
您最近一年使用:0次
【推荐1】在①
,②
,③
这三个条件中任选一个,补充在下面的问题中,并解答.
问题:设
是数列
的前n项和,且
,______________,求
的通项公式,并判断
是否存在最大值,若存在,求出最大值;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8dab76f8cbef0a3663d370be014bd9b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d887c3dafa90b36fbeaff8abf053210.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9995dbae52770a9aeceac87590a4b53b.png)
问题:设
![](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/86fc336b4a83bf6d66c4afcc431597f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
您最近一年使用:0次
【推荐2】设
是数列
的前
项和,已知![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4775854d3c2fd897b6799b14201e9e89.png)
(1)求
,并证明:
是等比数列;
(2)求满足
的所有正整数
.
![](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/4775854d3c2fd897b6799b14201e9e89.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf464629fa321a6ff7401ab79f07083.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faf6a6abc3a6abef29b943543e92f7ee.png)
(2)求满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1cd756ad895dc5bf3dfd98622bc60eb4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
您最近一年使用:0次