1 . 我国南宋数学家杨辉1261年所著的《详解九章算法》一书里给出了杨辉三角,书中是用汉字来表示的,如图1.研究发现,杨辉三角可以由组合数来表示,如图2.
杨辉三角有很多有趣的性质,如杨辉三角的两个腰上的数字都是1,用组合数表示为
.请写出一条其他的性质,用组合数表示为:______ .从杨辉三角蕴含的规律可知:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/616fbb8c7348bf0f926404bba3df3ce4.png)
______ .
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/15/7a8aca28-ce0c-498a-bc45-e5b170667a8b.png?resizew=697)
杨辉三角有很多有趣的性质,如杨辉三角的两个腰上的数字都是1,用组合数表示为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7964ea245849a99ef5ad9d30295b1329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/616fbb8c7348bf0f926404bba3df3ce4.png)
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解题方法
2 . 为庆祝中国共产党成立100周年,某校合唱团组织“唱支山歌给党听”演唱快闪活动.合唱团选出6个人站在第一排,其中甲、乙作为领唱需要站在第一排的正中间,则这6个人的排队方案共有( )
A.24种 | B.48种 | C.120种 | D.240种 |
您最近一年使用:0次
2023-08-15更新
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486次组卷
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2卷引用:北京市东直门中学2021-2022学年高二下学期期中考试数学试题
3 . 如图,过原点斜率为k的直线与曲线
交于两点
,
,
①k的取值范围是
.
②
.
③当
时,
先减后增且恒为负.
以上结论中所有正确结论的序号是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12be206d66e65eb92ef08bad8cd8f71d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12a3efb79f35db8448f3391252ab7d4e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8df332f01628130c084fd46aaca0a4b7.png)
①k的取值范围是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd90676eb80fa1a5d35bffb087ef0a95.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75b2dbf7259a1d7d48b4626505b998f1.png)
③当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4356baccfdced22ad483b13700d27b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5fd6fcd3e83e25540a7f38d2c034fe6.png)
以上结论中所有正确结论的序号是( )
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/24/7720c496-535d-4d1a-bf7f-a41647a5bf6c.png?resizew=217)
A.① | B.①② | C.①③ | D.②③ |
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4 . (1)计算:
;
(2)求不等式的解集
.
(3)已知函数满足方程
,求
的解析式.
(4)已知函数
,求
的单调区间.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca4a1b50c0c33b06f7d12db0acb3426e.png)
(2)求不等式的解集
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4e53d5a74eec643e381ff8b9d17085d.png)
(3)已知函数满足方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0f5dd70e54064d97834cd1ba2f8a6fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
(4)已知函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b9e414ec03fac1109660b59e568c470.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
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5 . 已知数列
,
,
,
满足
且
,2,
,
,数列
,
,
,
满足
,2,
,
,其中
,
,2,
,
表示
,
,
,
中与
不相等的项的个数.
(1)数列
,1,2,3,4,请直接写出数列
;
(2)证明:
,2,
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/713ac1eb0d8cce55d51e62ef4a2b1634.png)
(3)若数列A相邻两项均不相等,且
与A为同一个数列,证明:
,2,
,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/140b9dbcada4ac2e5fe3cc30009bcd67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07096af3b99fd1cb11c31f19a2c6408e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84390c669bd7a961e2161106903fa103.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e61e241c6c220b3b4705a8c1a465d7b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92e99796887e62d6de33cead5e11c00e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07096af3b99fd1cb11c31f19a2c6408e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/713ac1eb0d8cce55d51e62ef4a2b1634.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f17923637012a75a01f309379c1909c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13423c094861baf4b759b7f3d8c3c226.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07096af3b99fd1cb11c31f19a2c6408e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a54d5182f8520bfd9e225d835e924bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/790aeea3e93a2565637c6e0a41bc8ec9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07096af3b99fd1cb11c31f19a2c6408e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/713ac1eb0d8cce55d51e62ef4a2b1634.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87d50740801f1809b06dad5152558069.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe0befe2083a287274113203f5ed6f3e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07096af3b99fd1cb11c31f19a2c6408e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/713ac1eb0d8cce55d51e62ef4a2b1634.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07096af3b99fd1cb11c31f19a2c6408e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/668d1dcf486145a68016aab72dc6a4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50a272adba0f1120109824440f0e252c.png)
(1)数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f344a2d8d76fad8cbecaffc44f11f907.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfe59c8f17cdb81bf5305909fa137d32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07096af3b99fd1cb11c31f19a2c6408e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/713ac1eb0d8cce55d51e62ef4a2b1634.png)
(3)若数列A相邻两项均不相等,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0157ed29461c0c3559684b07c381a0a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07096af3b99fd1cb11c31f19a2c6408e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/713ac1eb0d8cce55d51e62ef4a2b1634.png)
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2023-01-11更新
|
437次组卷
|
2卷引用:北京市第二中学2021-2022学年高二下学期期末数学试题
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6 . 根据国家高考改革方案,普通高中学业水平等级性考试科目包括政治、历史、地理、物理、化学、生物6门,考生可根据报考高校要求和自身特长,从6门等级性考试科目中自主选择3门科目参加考试,在一个学生选择的三个科目中,若有两个或三个是文史类(政治、历史、地理)科目,则称这个学生选择科目是“偏文”的,若有两个或三个是理工类(物理、化学、生物)科目,则称这个学生选择科目是“偏理”的.为了了解同学们的选课意向,从北京二中高一年级中随机选取了20名同学(记为
,
,2,
,19,20其中
是男生,
是女生),每位同学都各自独立的填写了拟选课程意向表,所选课程统计记录如表:
(1)从上述20名同学中随机选取3名同学,求恰有2名同学选择科目是“偏理”的概率;
(2)从北京二中高一年级中任选两位同学,以频率估计概率,记
为“偏文”女生的人数,求
的分布列和数学期望;
(3)记随机变量
,样本中男生的期望为
,方差为
;女生的期望为
,方差为
,试比较
与
;
与
的大小(只需写出结论).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50a272adba0f1120109824440f0e252c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c45176df950dfe48b8ca7eac08ee349.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f782d70309802445202487eee751cbdd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dc8086120dd40f8b841f0e3d674fd68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e266dafb2e8d23f1a572abc1be2a96fd.png)
学生科目 | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() |
政治 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |||||||||||
历史 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | ||||||||||
地理 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | ||||||||||
物理 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |||||||
化学 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |||||||||||
生物 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
(2)从北京二中高一年级中任选两位同学,以频率估计概率,记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
(3)记随机变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2af47421c0539033d70024966f39835.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0924ce3e7d756f9f222752c9db8fb6af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a961e29b5b0773f3fdb8cc7e2ceb8094.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64bad212e1d9b641464ff6178109167e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/517ff073109a22fb321274d83412ebee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0924ce3e7d756f9f222752c9db8fb6af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64bad212e1d9b641464ff6178109167e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a961e29b5b0773f3fdb8cc7e2ceb8094.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/517ff073109a22fb321274d83412ebee.png)
您最近一年使用:0次
2023-01-11更新
|
777次组卷
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6卷引用:北京市第二中学2021-2022学年高二下学期期末数学试题
北京市第二中学2021-2022学年高二下学期期末数学试题北京市海淀区中国人民大学附属中学2023届高三下学期开学摸底练习数学试题北京市人大附中2023届高三下学期2月开学考数学试题北京市广渠门中学2024届高三上学期开学考数学试题(已下线)7.3.2离散型随机变量的方差(分层作业)-【上好课】2022-2023学年高二数学同步备课系列(人教A版2019选择性必修第三册)(已下线)7.3.2 离散型随机变量的方差——课后作业(巩固版)
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7 . 设函数
,
,若曲线
上存在一点
,使得点
关于原点
的对称点在曲线
上,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec5748527c15e370dcf4230ad2d0e1b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c829c3f2e2765100d9cf414cc2e6203c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51c530f4b7491b95acb8ce3eef9aa09d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a1cfb60420ff7e72c1b9d64f69ae063.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
A.有最小值![]() | B.有最小值![]() |
C.有最大值![]() | D.有最大值![]() |
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8 . 香农定理是通信制式的基本原理.定理用公式表达为:
,其中
为信道容量(单位:
),
为信道带宽(单位:
),
为信噪比.通常音频电话连接支持的信道带宽
,信噪比
.在下面四个选项给出的数值中,与音频电话连接支持的信道容量
最接近的值是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74c21280da5add920dff0e366a46bf79.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d787ef00aad66473daeb31bd3b65bf0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72bc766cbead9ec6fb613abe669b0be2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60c91fa27331e9958df48fd5633432e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4127daf7bda6bd8eda3ca8edd6476979.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdddac11848fa96bd1670b77188a0f5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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2023-01-04更新
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200次组卷
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3卷引用:北京市密云区2022-2023学年高一上学期(12月)数学期末试题
北京市密云区2022-2023学年高一上学期(12月)数学期末试题安徽省马鞍山市第二中学2022-2023学年高一下学期开学考试数学模拟试题(1)(已下线)河南省济源市、平顶山市、许昌市2022届高三文科数学试题变式题1-5
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9 . “天问一号”是执行中国首次火星探测任务的探测器,该名称源于屈原长诗《天问》,寓意探求科学真理征途漫漫,追求科技创新永无止境.图(1)是“天问一号”探测器环绕火星的椭圆轨道示意图,火星的球心是椭圆的一个焦点.过椭圆上的点P向火星被椭圆轨道平面截得的大圆作两条切线
,则
就是“天问一号”在点P时对火星的观测角.图(2)所示的Q,R,S,T四个点处,对火星的观测角最大的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ec8858389f4c3156a946ba8bf0d8a7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45a8a837c11c07073da3ff751d70278.png)
A.Q | B.R | C.S | D.T |
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741次组卷
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7卷引用:北京市西城区北师大二附中2022-2023学年高二上学期12月月考数学试题
名校
解题方法
10 . 如图,在三棱柱
中,平面
平面
,侧面
是边长为2的正方形,
分别为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/5/44e29202-58ce-4e59-a9ae-6b55a7711348.png?resizew=199)
(1)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72f0d0e78101fef36a75b70ac7e7cf5b.png)
(2)请再从下列三个条件中选择一个补充在题干中,完成题目所给的问题.
①直线
与平面
所成角的大小为
;②三棱锥
的体积为
;③
. 若选择条件___________.
求(i)求二面角
的余弦值;
(ii)求直线
与平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91ba5715a95b8de18c637c12c3d30d7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72f0d0e78101fef36a75b70ac7e7cf5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d12b92bb195943c794a3b3cf135d71a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ddef39ef9ed3da136c4ed8b5d28b73e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/5/44e29202-58ce-4e59-a9ae-6b55a7711348.png?resizew=199)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72f0d0e78101fef36a75b70ac7e7cf5b.png)
(2)请再从下列三个条件中选择一个补充在题干中,完成题目所给的问题.
①直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15615de1a6df206dbd081251f676578e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8da67af246912670bac6dc860f301383.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff4fcf607b0710d12aaabd17fd053d83.png)
求(i)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34ecc467cf90f9f26cf6902af77427ca.png)
(ii)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72f0d0e78101fef36a75b70ac7e7cf5b.png)
您最近一年使用:0次
2023-01-03更新
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884次组卷
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3卷引用:北京市海淀实验中学2023届高三上学期期末数学试题
北京市海淀实验中学2023届高三上学期期末数学试题第八章立体几何初步章节验收测评卷-【精讲精练】2022-2023学年高一数学下学期同步精讲精练(人教A版2019必修第二册)(已下线)重难点突破02 利用传统方法求线线角、线面角、二面角与距离(四大题型)