1 . 已知数列
的首项
,且
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d5a99603dd831f8b3612245fa2303f5.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05d4f2dc952ce53ed4bd6f56f3aa6ffa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d5a99603dd831f8b3612245fa2303f5.png)
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2 . 正项数列
满足
,
.
(1)证明:数列
为等比数列;
(2)求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/723e99fc83a17217be0435ae9f3650c4.png)
(1)证明:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e2de706dc5f0439b989273a5367f63a.png)
(2)求数列
![](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)
您最近一年使用:0次
2024-04-15更新
|
1109次组卷
|
2卷引用:新疆维吾尔自治区塔城市塔城地区第一高级中学2023-2024学年高二下学期5月期中考试数学试题
名校
3 . 设等比数列
的公比为
为前
项和,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42e4487468ab2823d6dbf7f0ebd2eb38.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12987b03c38b4ada5aed3f5e12b23852.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88eabdbd7d8bdc68bdf782b360cbb889.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42e4487468ab2823d6dbf7f0ebd2eb38.png)
您最近一年使用:0次
4 . 已知等比数列
的公比与等差数列
的公差均为2,且
,设数列
满足
,
,则数列
的前20项的和为( )
![](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/466439a6a693de6d50c5bbef04ec81c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/850248748bcab582d2aa2a3093d088cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e145b6046bc80d0ffecc61ac67c87ca1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2024-03-08更新
|
871次组卷
|
3卷引用:新疆乌鲁木齐市第十九中学2023-2024学年高二下学期第二次月考数学试题
名校
5 . 设等差数列数列
的前
项和为
,若
,则
( )
![](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/39119df34faa2d46049ff12968f08ea6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/554e6c461ccc5aa3093c524aa528a4e2.png)
A.30 | B.28 | C.26 | D.24 |
您最近一年使用:0次
6 . 利用温室大棚等设施进行蔬菜种植,可以使得人们在一年四季吃上夏季的新鲜蔬菜,造福民生.某地大棚种植户现要采购一批圆筒状地膜,发现该种圆筒状地膜由纸质圆柱形空筒和缠绕在纸筒外面的地膜构成,经测量得到圆柱形空筒底面圆的半径为3cm(纸质圆筒的厚度忽略不计),每层地膜的厚度为0.1mm,约定在计算每层地膜的长度时,以外层半径来进行,则一筒100层的地膜的总长度大约为( )(
,结果精确到1m)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51daf26574eb163dfc6f39dd37a211b3.png)
A.18m | B.19m | C.20m | D.21m |
您最近一年使用:0次
2024-03-04更新
|
80次组卷
|
2卷引用:新疆兵团地州学校2023-2024学年高二上学期期末联考数学试题
解题方法
7 . 已知等差数列
中,
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af0a8e313d86fb85b3666b2b6b554efa.png)
(1)求
的通项公式
(2)求数列
的前n项和
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb334e165679c6cb500c994cffa47147.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af0a8e313d86fb85b3666b2b6b554efa.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)求数列
![](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
解题方法
8 . 设等差数列
的前n项和为
﹐若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a6d3d768cd00a21b3aca22aa64ac3c4.png)
____ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3903653955c424d3f6135edc5b47e231.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df2111370b3a3b575b7cac52bec12395.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a6d3d768cd00a21b3aca22aa64ac3c4.png)
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9 . 不等式
的解集是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6436b17f3d902199864aad605ebb9395.png)
A.![]() | B.![]() |
C.![]() | D.![]() ![]() |
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10 . 蚊香具有悠久的历史,我国蚊香的发明与古人端午节的习俗有关.如图,为某校数学社团用数学软件制作的“蚊香”.画法如下:在水平直线上取长度为1的线段AB,作一个等边三角形ABC,然后以点B为圆心,AB为半径逆时针画圆弧交线段CB的延长线于点D(第一段圆弧),再以点C为圆心,CD为半径逆时针画圆弧交线段AC的延长线于点E,再以点A为圆心,当得到的“蚊香”恰好有9段圆弧时,“蚊香”的长度为( )
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/21/e2cc26ea-fe32-4340-915e-ea82e7ec0279.png?resizew=292)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/21/e2cc26ea-fe32-4340-915e-ea82e7ec0279.png?resizew=292)
A.14π | B.18π | C.24π | D.30π |
您最近一年使用:0次