20-21高三下·河南·阶段练习
解题方法
1 . 已知数列
是公差为
的等差数列,设
,若存在常数
,使得数列
为等比数列,则
的值为___________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db7877e1ae6cc8a0474e322300e874fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c82e58147cbcdaa4dbc35b4a2df030e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
您最近一年使用:0次
2021-02-23更新
|
794次组卷
|
7卷引用:押第15题 数列-备战2021年高考数学(理)临考题号押题(全国卷1)
(已下线)押第15题 数列-备战2021年高考数学(理)临考题号押题(全国卷1)(已下线)专题10 数列(难点)-2020-2021学年高二数学下学期期末专项复习(北师大版2019选择性必修第一册、第二册)(已下线)专题09 《数列》中的存在性问题-2021-2022学年高二数学同步培优训练系列(苏教版2019选择性必修第一册)(已下线)河南省九师联盟2020-2021年高三下学期2月联考理科数学试题(已下线)专题09 数列的通项公式、数列求和及综合应用(练习)-1(已下线)压轴小题6 等差数列求参数(已下线)第四章 数列(单元重点综合测试)-2023-2024学年高二数学单元速记·巧练(苏教版2019选择性必修第一册)
2 . 设
是实数,
是整数,若
,则称
是数轴上与
最接近的整数.
(1)数列
的通项为
,且对任意的正整数
,
是数轴上与
最接近的整数,写出一个满足条件的数列
的前三项;
(2)数列
的通项公式为
,其前
项和为
,求证:整数
是数轴上与实数
最接近的整数;
(3)
是首项为
,公比为
的等比数列的前
项和,
是数轴上与
最接近的正整数,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5030b4c9e28df695266e5d9578e0365.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(1)数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b80c1ed7b10ac7ca1cd81cdd39a8fcc0.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/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b0cfe24f4698eaed9c426b24b4c9f69.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82e260b088f071983f254ce8f5163fcd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bef5f36035455d7934efd8ffd671efc4.png)
您最近一年使用:0次
3 . 已知数列
的首项
,且满足
,则存在正整数n,使得
成立的实数
组成的集合为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
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A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2022-01-03更新
|
1304次组卷
|
5卷引用:专题09 《数列》中的存在性问题-2021-2022学年高二数学同步培优训练系列(苏教版2019选择性必修第一册)
(已下线)专题09 《数列》中的存在性问题-2021-2022学年高二数学同步培优训练系列(苏教版2019选择性必修第一册)江西省宁冈中学2021-2022学年高二10月份段考数学试题【全国校级联考】2018年高考第二次适应与模拟数学(理)试题江苏省南京市第十三中学2020-2021学年高二上学期12月阶段学情调研数学试题辽宁省沈阳市第一二〇中学2021-2022学年高二下学期第一次月考数学试题
解题方法
4 . 在正项等差数列
和正项等比数列
中,下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
A.若![]() ![]() |
B.若![]() ![]() ![]() ![]() |
C.若![]() ![]() ![]() |
D.若![]() ![]() ![]() ![]() ![]() ![]() ![]() |
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5 . 如图,P1是一块半径为2a的半圆形纸板,在P1的左下端剪去一个半径为a的半圆后得到图形P2,然后依次剪去一个更小的半圆(其直径为前一个被剪掉半圆的半径)得图形P3、P4、…、Pn、…,记第n块纸板Pn的面积为Sn,则(1)S3=______ ,(2)如果对
恒成立,那么a的取值范围是______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dda9d388b425884d91f4f18ca07d060d.png)
![](https://img.xkw.com/dksih/QBM/2021/4/17/2701661097025536/2705910288343040/STEM/71df5225-ed95-4832-80db-fcb430ea0494.png?resizew=631)
您最近一年使用:0次
2021-04-23更新
|
817次组卷
|
9卷引用:专题05 等比数列的前n项和公式 核心素养练习 -【新教材精创】2020-2021学年高二数学新教材知识讲学(人教A版选择性必修第二册)
(已下线)专题05 等比数列的前n项和公式 核心素养练习 -【新教材精创】2020-2021学年高二数学新教材知识讲学(人教A版选择性必修第二册)(已下线)卷04 等比数列 A卷 ·基础达标 -【重难点突破】2021-2022学年高二数学名校好题汇编同步测试卷(人教A版选择性必修第二册)(已下线)第二章 推理与证明(能力提升)-2020-2021学年高二数学单元测试定心卷(人教版选修2-2)(已下线)第四章 数列单元测试B卷-【新高考题型】2020-2021学年高二数学下学期单元实战演练AB卷(人教A版2019)北师大版(2019) 选修第二册 名师精选 第三单元 等比数列 A卷北师大版(2019) 选修第二册 突围者 第一章 数列 易错疑难集训(三)广东省汕头市金山中学2019-2020学年高二上学期期末考试数学试题人教A版(2019) 选择性必修第二册 过关斩将 第四章 数列 4.3 等比数列 4.3.2 等比数列的前n项和公式 第2课时 等比数列前n项和的综合运用2023版 湘教版(2019) 选修第一册 过关斩将 第1章 数列
解题方法
6 . 已知数列
的前
项和为
,
,
,数列
满足
,
,对任意
,都有
.
(1)求数列
、
的通项公式.
(2)令
,若对任意的
,不等式
恒成立,试求实数
的取值范围.
![](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/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd364a41464b2f3fb38c4b764a2e9084.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a24e6bcf49b8e45531a2d4e4c70c181.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f13851bcbbcaacbf03b62e88757e0b9.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2df6984da27bd9fab1592897117059c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f093c61867ee4ce75f951d46b9b123.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb7489d944366fe8cb29d3b7ccf7d5e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
您最近一年使用:0次
解题方法
7 . 已知数列
的通项公式是
,在
和
之间插入1个数
,使
,
,
成等差数列;在
和
之间插入2个数
,
,使
,
,
,
成等差数列;
;在
和
之间插
个数
,
,
,
,使
,
,
,
,
,
成等差数列.这样得到新数列
;
,
,
,
,
,
,
,
,
,
,
记数列
的前
项和为
,有下列判断:①
;②
;③
;④
,其中正确的判断序号是______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e4b5779873cb3f4366dbfdb983dec81.png)
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您最近一年使用:0次
解题方法
8 . 已知数列
中,其前
项和为
,且满足
,数列
的前
项和为
,若
对
恒成立,则实数
的取值范围是( )
![](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/b3d4fe74f5287a2e23d9e8912714f1cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/362832fa3d3c13c1eafd565349d66dce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fef2b2086745f9fe190274699cc08b82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cea4ac187cbb465180e89f38250b3970.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
您最近一年使用:0次
2020-12-03更新
|
1115次组卷
|
4卷引用:4.3.3 等比数列的前n项和(2)-2021-2022学年高二数学同步培优训练系列(苏教版2019选择性必修第一册)
(已下线)4.3.3 等比数列的前n项和(2)-2021-2022学年高二数学同步培优训练系列(苏教版2019选择性必修第一册)(已下线)专题08 《数列》中的恒成立问题-2021-2022学年高二数学同步培优训练系列(苏教版2019选择性必修第一册)(已下线)江苏省苏锡常镇四市2023届高三下学期3月教学情况调研(一)数学试题变式题6-10吉林省通榆县第一中学2020-2021学年高三上学期期中考试数学(理)试题
2020·全国·模拟预测
9 . 某市为大力推进生态文明建设,把生态文明建设融入市政建设,打造了大型植物园旅游景区.为了了解游客对景区的满意度,市旅游部门随机对景区的100名游客进行问卷调查(满分100分),这100名游客的评分分别落在区间
,
,
,
,
内,且游客之间的评分情况相互独立,得到统计结果如频率分布直方图所示.
![](https://img.xkw.com/dksih/QBM/2020/11/24/2599712562765824/2599753786359808/STEM/00d46b9e-d79a-4ac1-a908-055b2e20f715.png?resizew=368)
(1)求这100名游客评分的平均值(同一区间的数据用该区间数据的中点值为代表);
(2)视频率为概率,规定评分不低于80分为满意,低于80分为不满意,记游客不满意的概率为
.
(ⅰ)若从游客中随机抽取
人,记这
人对景区都不满意的概率为
,求数列
的前4项和;
(ⅱ)为了提高游客的满意度,市旅游部门对景区设施进行了改进,游客人数明显增多,对游客进行了继续旅游的意愿调查,若不再去旅游记1分,继续去旅游记2分,每位游客有继续旅游意愿的概率均为
,且这次调查得分恰为
分的概率为
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b57e2bfe23e15caa08f0be5eabd5a18a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/198d01d4dec27248f2107e647b2b8388.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c301143e835b3675a43f15b3d33f2bc7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686c7282d079715d74fe77757464694d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9cf83dc956b78d5454067973fed1a33.png)
![](https://img.xkw.com/dksih/QBM/2020/11/24/2599712562765824/2599753786359808/STEM/00d46b9e-d79a-4ac1-a908-055b2e20f715.png?resizew=368)
(1)求这100名游客评分的平均值(同一区间的数据用该区间数据的中点值为代表);
(2)视频率为概率,规定评分不低于80分为满意,低于80分为不满意,记游客不满意的概率为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
(ⅰ)若从游客中随机抽取
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/681ae1522a36768618f7ddaf74abbb7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7ad607e7223cab89fb899e5c1716b4d.png)
(ⅱ)为了提高游客的满意度,市旅游部门对景区设施进行了改进,游客人数明显增多,对游客进行了继续旅游的意愿调查,若不再去旅游记1分,继续去旅游记2分,每位游客有继续旅游意愿的概率均为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63f5c583c98a1fd516c6ceaa60b55dec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a821e643d5fae24caed0faa6d423dad6.png)
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10 . 定义:对于一个项数为
的数列
,若存在
且
,使得数列
的前
项和与剩下项的和相等(若仅为1项,则和为该项本身),我们称该数列是“等和数列”例如:因为3=2+1,所以数列3,2,1是“等和数列”.请解答以下问题:
(1)数列
是“等和数列”,求实数
的值;
(2)设数列
通项公式为
,且共有
项,证明:
不是等和数列;
(3)项数为
的等差数列
的前
项和为
,求证:
是“等和数列”
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fdcd07be0a24101e784b628d46ec90f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46b6d151d3f864bae873987f6db9327a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfae43a1ea1f5f3a031d224ac61a5f37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
(1)数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca2c6eaa1e1c1f4c85e35b46e30b7c70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
(2)设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b933d363f5b85a6b4110c9ef030c56a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(3)项数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/378397148dc9a98bb9109154a551ced5.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/f899bd706e363ec439acbd0bea356209.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
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