1 . 侏罗纪蜘蛛网是一种非常有规律的蜘蛛网,它是由无数个正方形环绕而成.如图正方形
的边长为1,取其四边的三等分点
,
,
,
,作第二个正方形为
,然后再取正方形
各边的三等分点
,
,
,
,作第三个正方形
,依次方法持续下去…,则第7个正方形的周长是______ ,如果这个作图过程可以一直继续下去,则所有这些正方形的周长之和将趋于______ .(填数值)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd3b9e816b14051f785aa5aae72b8eed.png)
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2 . “无字证明”就是将数学命题用简单、有创意而且易于理解的几何图形来呈现.请观察图,根据半圆中所给出的量,补全三角恒等式![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b85be3917998d2f99b9eb3cbac115c3d.png)
,第一个括号为 ______ ,第二个括号为_______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b85be3917998d2f99b9eb3cbac115c3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9368c5c47e686f10cfdafc0a26d5b8dc.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/80a82fde-0127-4a04-9e66-e65a3af4ee53.png?resizew=232)
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3 . 已知一组数据
的平均数为
,方差为
,则这组数据的平均数![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd141a9d19473cab037c5e918f722e18.png)
______ ;若新增3个均为
的数据,方差记为
,那么![](https://staticzujuan.xkw.com/quesimg/Upload/formula/926eac04c657327fe496fdf49f023e66.png)
______
(填写“
”、“
”或“
”)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/569962d9dfea9c5b893d88b1fee19085.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80746e5e22851a0f1075374a3c3280ad.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd141a9d19473cab037c5e918f722e18.png)
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4 . 已知
:
,
,则
:________ ,
是________ 命题.(填写“真”或“假”)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ad5fe274cfc8da2dacfb65801f344ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46ad23dae9c388a54006d030ae4c9588.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ffc1bb9d53a27d484396ad74d6a26e0.png)
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5 . 已知变量x和y满足关系
,变量y与z负相关,则可以判断变量x与y______ ,x与z______ .(填写“正相关”或“负相关”)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa6342e0a5a8942cfb1cf535ceb2c50d.png)
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解题方法
6 . 一般认为,民用住宅的窗户面积必须小于地板面积,但窗户面积与地板面积的比应不小于10%,而且这个比值越大,采光效果越好.若一所公寓窗户面积与地板面积的总和为220
,则这所公寓的地板面积至多为___________ 平方米;若同时增加相同的窗户面积和地板面积,公寓的采光效果是______________ (填写“变好了”或者“变坏了”)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35c901bcdfa58f0c68ad0161b0bab269.png)
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7 . 如图,已知圆
的半径为定长
是圆
所在平面内一个定点,
是圆上任意一点,线段
的垂直平分线
和直线
相交于点
.当点
在圆上运动时:(1)当点A在圆
内且不与点
重合时,点
的轨迹是__________ (从圆、椭圆、抛物线中选择一个填写);(2)当![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50c0700b92ddfc927f81fa96059d70e9.png)
__________
(从>,=,<中选择一个填写)时,点
的轨迹是双曲线的一支.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/694032f6e765cbb0391c87c41ad629f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
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![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/24/6d6582d9-f283-4315-9dd9-b57b5603cb14.png?resizew=96)
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2023-01-18更新
|
237次组卷
|
3卷引用:山东省菏泽市2022-2023学年高二上学期期末数学试题
名校
解题方法
8 . 已知某批产品共20件,其中二等品有8件.从中任意抽取2件,
表示取出的2件产品中二等品的件数,试填写下列关于
的分布列.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![]() | 0 | 1 | 2 |
![]() | ![]() |
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2022-07-09更新
|
333次组卷
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5卷引用:湖北省新高考联考协作体2021-2022学年高二下学期期末数学试题
湖北省新高考联考协作体2021-2022学年高二下学期期末数学试题湖北省孝感市2021-2022学年高二下学期期末数学试题(已下线)4.2.3二项分布与超几何分布(2)(已下线)8.2.4超几何分布(1)(已下线)8.2 离散型随机变量及其分布列(3)
名校
9 . 已知空间中两条不同的直线
和平面
,给出三个论断:①
;②
;③
.请以其中两个论断作为条件,另一个为结论,写出一个真命题:若________ ,则________ .(填写相应序号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/280860dd039e1305a5ccc455f63e8223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fe920cd78db25f5b4df37d066e57800.png)
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10 . 如图,在棱长为
的正方体
中,
,
,
,
分别为棱
,
,
,
的中点,点
在四边形
及其内部运动,
是棱
上的点.当![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d483c4accd0aeafc4a83ff960f4e5c4d.png)
__________ 时(在线上填入确定的常数),若
,则动点
的轨迹长为__________ (填写一组关系即可).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f8c4c029e552954bd493b49aeab82d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f43488162b69d750f069b89a8b2d80f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/23/857f5a77-82d2-428a-b047-739420297b50.png?resizew=220)
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2022-03-31更新
|
430次组卷
|
3卷引用:湖北省黄石市有色一中2021-2022学年高二上学期10月月考数学试题