解题方法
1 . 九连环是我国从古至今广泛流传的一种益智游戏.九连环由九个相互连接的环组成,这九个环套在一个中空的长形柄中.九连环的每个环互相制约,只有第一环能够自由上下.要想解下(或安上)第n个环,就必须满足以下两个条件(第一个环除外):①第
个环在架上;②第
个环前面的环全部不在架上.记解下n连环所需的最少移动步数为
,已知
,
,
,则解下六连环所需的最少移动步数为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c0cdbf7b7cb42491810101c6e0db4ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c0cdbf7b7cb42491810101c6e0db4ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4469d0f72ac0f7fa66f40414d964c356.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f966272f7781790ff27e40db6b525253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb3ab0739736b96ecfdc64ee7952f98c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/10/22bf2c93-d45f-4d32-8be6-e52112c064e3.png?resizew=181)
A.31 | B.64 | C.256 | D.341 |
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2 . 若实数x、y满足约束条件
,则
的最小值是______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81f69aec4c628b5aa3a7ae9e7add59a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4489516aca67a6afe53fac2f1477f76.png)
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3 . 在各项均为正数的等比数列
中,
,则
的最大值是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56cd67becd565552c080c6ac2966a26c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1728003683a0df51fe17ca8711f3b341.png)
A.25 | B.5 | C.![]() | D.![]() |
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2023-08-09更新
|
704次组卷
|
2卷引用:陕西省西安市周至县2020-2021学年高三一模文科数学试题
解题方法
4 . 设
是等差数列
的前n项和,且
,
,则公差
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0078f6d65d99ed5ac0bf789fbf87348f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2cb4485663835fc40a9cf82f491d5b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c98c59cd4749afdd21e73529fc84323.png)
A.1 | B.2 | C.5 | D.6 |
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2023-08-09更新
|
422次组卷
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2卷引用:陕西省西安市周至县2020-2021学年高三一模文科数学试题
5 . 对于数列
,若存在正整数
,使得
,
,则称
是数列
的“谷值”,k是数列
的“谷值点”.在数列
中,若
,则数列
的“谷值点”有( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0505b3b01eabf49fa1cd907fe92deb03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e5cf452212a968ba9f8adab79c04e40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eda15e9f9a1f317f45a468712700e546.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f255d0395fba51ca2d44293cca42e0a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f17e2f884676842e1d7d05cd4ab06ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
A.1个 | B.2个 | C.3个 | D.无数个 |
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6 . 设等比数列
的前n项和为
,若
,公比
,
,
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9645bd4d2002993b90ec6d48f9c04f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eda6dc559d07bc22c9a0ed1e3a6d01d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22c5c4ac959eb2c4b74afabc9cdd3a6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e55feca124a3c380c2e7089c897da73e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9620357ea5be4037cfdccd09a27d3862.png)
A.15 | B.20 | C.31 | D.32 |
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2023-08-09更新
|
725次组卷
|
3卷引用:陕西省西安市周至县2020-2021学年高三一模理科数学试题
名校
解题方法
7 . 在
中,角
的对边分别是
,且
.
(1)求证:
;
(2)若
,求
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fb62f6a1a906f86ae0448d6b4ff6fd6.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02746ec8e4220d8b4a174d5e9a711ed2.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2293e25112b028c10edbf063146ecb3a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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8 . 如图,为测量某信号塔
的高度,选择与塔底
在同一水平面上的
两点为观测点(假设
平面
).在
处测得塔顶
的仰角为
,在
处测得塔顶
的仰角为
.若
米,
,则信号塔
的高为__________ 米.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef49a3ca580a144cc65a609c167facc1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3e126c16032892966489053f44b9048.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274a77343ecde1c2665df291761b6563.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ac09dc1ca2cdd7aef28c218763d3e4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e5fa72f2878b476bc57f0df12d6555.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3dd4997da49b3dfe98144ad13aed0d5c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f4fe1cbf214469abfa2fefc60a9a3dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef49a3ca580a144cc65a609c167facc1.png)
![](https://img.xkw.com/dksih/QBM/2023/8/5/3296082552881152/3297964894281728/STEM/3978e57a908c4b35893a2721bb4c715a.png?resizew=125)
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2023-08-07更新
|
194次组卷
|
2卷引用:陕西省榆林市神木中学2021届高三三模文科数学试题
名校
解题方法
9 . 已知正项等比数列
的前
项和为
,若
成等差数列,
.
(1)求
与
;
(2)设
,数列
的前
项和记为
,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/5bff10824ab9a9e1351b07569820399e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9824bccea52966ead370db7729f61c3b.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a90ee20557326d7d408a75ab26c70b37.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/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
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2023-04-26更新
|
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17卷引用:陕西省2021届高三下学期教学质量检测测评(五)理科数学试题
陕西省2021届高三下学期教学质量检测测评(五)理科数学试题山西省吕梁市2021届高三三模数学(理)试题重庆市第八中学2021届高三下学期第五次模拟数学试题(已下线)“超级全能生”2021届高三全国卷地区5月联考试题(乙卷)数学(理)试题(已下线)“超级全能生”2021届高三全国卷地区5月联考试题(甲卷)数学(理)试题四川省成都外国语学校2020-2021学年高一下学期6月月考数学(理)试题四川省泸州市泸县第四中学2022-2023学年高三下学期第二次诊断性模拟考试数学(理)试题四川省泸州市泸县第四中学2023届高三下学期二诊模拟考试数学(文)试题四川省泸县第四中学2023届高三第二次诊断性模拟考试数学(理科)试题陕西省西安市雁塔区第二中学2022-2023学年高二下学期第二次阶段性测评理科数学试题陕西省西安市雁塔区第二中学2022-2023学年高二下学期第二次阶段性测评文科数学试题陕西师范大学附属中学渭北中学2022-2023学年高二下学期5月月考理科数学试题西藏昌都市第一高级中学2023届高三高考全真仿真考试数学(理)试题四川省泸州市泸县第一中学2021-2022学年高一下学期期中考试数学试题青海省西宁市六校联考2022-2023学年高三下学期开学考试数学(理)试题四川省凉山州宁南中学2022-2023学年高二下学期第二次月考理科数学试题新疆生产建设兵团第六师芳草湖农场中学2021-2022学年高二上学期期末数学(理)试题
10 . 已知数列
是递增数列,
,且
.若
,则正整数
( )
![](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/524f2313bf15c276605f916405b4d847.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90862eca0071c91262a7729c94642b66.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd707b69a11f8de5566f23c1a2a9ff5a.png)
A.9 | B.10 | C.11 | D.12 |
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