名校
1 .
,
是正项等比数列.且
,且
,
(1)求
的通项公式;
(2)设
,求数列
的前n项和
![](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/9601e1941365bca8dbe7034a5b57e80d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee3650c564625b7887d090dd50004e66.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5735123ce8ca6c58761ee4b789bb187.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38ef4c4439b36c2847b0056a116d56d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次
23-24高二上·上海·课后作业
2 . 已知等比数列
的前5项和为10,前10项和为50,求这个数列的前15项和.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
您最近一年使用:0次
23-24高二上·全国·课后作业
3 . 已知等比数列
的前
项和为
.
(1)求证:当公比
时,
,
,
成等比数列;
(2)求证:
,
,
成等比数列;
(3)试推广(1)和(2)的结果,写出你的结论并加以证明.
![](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)
(1)求证:当公比
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/354efd9145bb3bd889cf0eaadbcc55f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e147c1f8b0941586a7cc61e9b0d7879.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a012e9ffdbe44925133a1754e9031fae.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6899bf9cadae2ccdb14cbc87d4f280ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/142bd84f63530e1fdf2cc53ab3a14037.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4740344514cb6f1de52d3a2d8c3ee087.png)
(3)试推广(1)和(2)的结果,写出你的结论并加以证明.
您最近一年使用:0次
4 . 已知等比数列
中,前
项和为
,且
,
.求
.
![](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/8c9b5080aa2e9c889aac8e378d83dfee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7216dd4c5b22df4eb825b56ad060b9c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d16765bfe96c4c2733afdf4099a33f5e.png)
您最近一年使用:0次
5 . 在等比数列
中,已知
,
,其前n项和为
.求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f379399f52f946d7b7b485bd556e9aa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97f5c05fd185d13caadc3161ccdc68d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a48e81b54f78b96294295542b010dfb.png)
您最近一年使用:0次
21-22高二·江苏·课后作业
6 . 已知{an}为等比数列,且Sn=a,S2n=b(ab≠0),求S3n.
您最近一年使用:0次
20-21高二·全国·课后作业
7 . 设等比数列{
}的前n项和为Sn,且S4=1,S8=7,求S12.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
您最近一年使用:0次
20-21高二·全国·课后作业
8 . 在等比数列
中,已知Sn=48,S2n=60,求S3n.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
您最近一年使用:0次
20-21高二·全国·课后作业
9 . 如果一个等比数列前5项的和等于10,前10项的和等于50,那么这个数列前15项的和等于多少?
您最近一年使用:0次
20-21高二·全国·课后作业
10 . 已知等比数列
的前
项和为
,且
,
,求
的值.
![](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/06f4d64db78e0331ea922eebc9f1ae02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/296e8563c34af1f5bdfc681da64190cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fa209ac86cd8c88e638cda47db5bfa2.png)
您最近一年使用:0次