解题方法
1 . 现有甲、乙两个盒子中都有大小、形状、质地相同的2个红球和1个黑球.从两个盒子中各任取一个球交换,记为一次操作.重复进行
次操作后,记甲盒子中黑球个数为
,甲盒中恰有1个黑球的概率为
,恰有2个黑球的概率为
.
(1)求随机变量
的分布列;
(2)求数列
的通项公式;
(3)求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6368fec0c2c25db7c29b014d60270e97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93d0f3799612b81e85b87241ec8eee68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
(1)求随机变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/096b1ece1dcd29c59a46a4b3e02cb548.png)
(2)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(3)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e067aeb203bc5ce00c9dc47aa34cee5e.png)
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解题方法
2 . 已知函数
在
上单调递增,在
上单调递减,设
为曲线
的对称中心.
(1)求
;
(2)记
的角
对应的边分别为
,若
,求
边上的高
长的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8dfa22404f8f7208b7601367dcc75d4e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35f56f79c0b80b7340be885e4dad6901.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30a960e24187acf3a6e5075fb31ca1c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9938230f82e91cf09f8157b532baaba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79b752f0f189e5d8666daea73e145dff.png)
(2)记
![](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/275a078c4e7732e05ae34c754f03417b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
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3 . 在某次数学练习中,高三班的男生数学平均分为120,方差为2,女生数学平均分为112,方差为1,已知该班级男女生人数分别为25、15,则下列说法正确的有( )
A.该班级此次练习数学成绩的均分为118 |
B.该班级此次练习数学成绩的方差为16.625 |
C.利用分层抽样的方法从该班级抽取8人,则应抽取5名男生 |
D.从该班级随机选择2人参加某项活动,则至少有1名女生的概率为![]() |
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解题方法
4 . 甲和乙两个箱子中各装有
个大小、质地均相同的小球,并且各箱中
是红球,
是白球.
(1)当
时,从甲箱中随机抽出2个球,求2个球的颜色不同的概率.
(2)由概率学知识可知,当总量
足够多而抽出的个体足够少时,超几何分布近似为二项分布,现从甲箱中不放回地取3个小球,恰有2个白球的概率记作
;从乙箱中有放回地取3个小球,恰有2个白球的概率记作
.
①求
,
.
②当
至少为多少时,我们可以在误差不超过0.001(即
)的前提下认为超几何分布近似为二项分布?(参考数据:
).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eac97e6740365c85ad857aff85cefbe5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d33adb74906403b0b00fcbd9fa691d8b.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebcc133d5b11b33a904875182d8c8261.png)
(2)由概率学知识可知,当总量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2708fa6298e52f617383efc175b71ddc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b9cb8e6ff801523b0304576cd69fd2d.png)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2708fa6298e52f617383efc175b71ddc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b9cb8e6ff801523b0304576cd69fd2d.png)
②当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc8ad1462305b4399657e139e7e3053f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6be80dfcf339d34d2b419818023574db.png)
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解题方法
5 . 已知函数
,数列
满足
,
,
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c34d64a7bea0629324b9105d94556ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8323901a49cac29afd7d62864f088077.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90ce53d78a1931364b237324fc72e592.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14a18d2df798894e2515f8f14b76624f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7904757c16ce6903bd5580d2c37ed11.png)
A.1 | B.2 | C.3 | D.4 |
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6 . 已知集合
,
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84b26fdc500ce6feacd6e3960143ef5d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd108092d5bb927be39ef36a395aa8d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1336d38741aab2255a35c26612bbd7cc.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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解题方法
7 . 现有
个编号为
的小球,随机将它们分成甲、乙两组,每组
个. 设甲组中小球的最小编号为
,最大编号为
;乙组中小球的最小编号为
,最大编号为
记
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af08d7880119cf28597caa5b8bc2318b.png)
(1)当
时,求
的分布列和数学期望;
(2)令
表示“事件
与
的取值恰好相等”.
①求事件
发生的概率
;
②证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d51f9147b8265c0276c1f2c2659197.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9cd1cd466cd9c2efac66912e0d4cd188.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.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/b715e7842b95f654f16056a7c7f2abe9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbda50272b74d847ec25ee9bf89b48ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37f38b2f8c48333ec2e7749a83fcd0c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af08d7880119cf28597caa5b8bc2318b.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be604061cf1591f7069472269d4c9719.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5c1116ce7f5a1a7b57517276d5092fa.png)
①求事件
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a244cf6ac956323ea14e09c5e175448.png)
②证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61cd2de30ea549eddd97b1a1c81bf092.png)
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解题方法
8 . 已知箱中有若干个大小相同的红球和白球,每次抽一个球,若抽到白球,则放回并再次抽球,若抽到红球,则不再抽取.设每次抽到红球的概率为p(
),记X为停止抽球时所抽取的次数,X的数学期望为
.
(1)若最多抽4次,且
,求X的分布列及数学期望;
(2)在成功概率为p(
)的伯努利试验中,记X为首次成功时所需的试验次数,X的取值为所有正整数,此时称离散型随机变量X的概率分布为几何分布.若抽球一直进行下去,则X服从几何分布.
①求恰好第k次抽到红球的概率
;
②求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20c11f6c800b8e0410674a0c6d307d26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bf3baba074e8aeb6f3ea117865bbd1b.png)
(1)若最多抽4次,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09e5a154944cfae71a14d3da122dd08e.png)
(2)在成功概率为p(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20c11f6c800b8e0410674a0c6d307d26.png)
①求恰好第k次抽到红球的概率
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef133b0fd53a48310a82c18729575abd.png)
②求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bf3baba074e8aeb6f3ea117865bbd1b.png)
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9 . 下列说法正确的有( )
A.直线![]() ![]() |
B.两个平面的夹角的范围是![]() |
C.数据25,32,33,40,45的第70百分位数为40 |
D.用决定系数![]() ![]() |
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解题方法
10 . 已知
,
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dae5a9f33df69fd5f97f9c2dce934ec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf9659af61c4dd462d7962be86d0e329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4b9b470218359a4a47be9244980489e.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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