名校
1 . 某生产线正常生产状态下生产的产品
的一项质量指标
近似服从正态分布
,若
,则实数
的值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d9cf60139c539ba74a33afcb70d6688.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae3e75e7296a5b55d20822ca4aecc451.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
A.![]() | B.![]() | C.10 | D.19 |
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2 . 如图所示,圆台的母线与下底面的夹角为,上底面与下底面的直径之比为
,
为一条母线,且
,
为下底面圆周上的一点,
,则( )
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/20/64fc664f-8eff-424a-98f7-64cf4fa07fc1.png?resizew=161)
A.三棱锥![]() | B.圆台的表面积为![]() |
C.![]() ![]() | D.直线![]() ![]() ![]() |
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解题方法
3 . 已知直线
与抛物线
:
交于
,
两点.
是线段
的中点,点
在直线
上,且
垂直于
轴.
(1)求证:
的中点在
上;
(2)设点
在抛物线
:
上,
,
是
的两条切线,
,
是切点.若
,且
位于
轴两侧,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cf8085c9d6fc73d634c7c316a14df78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1241216f3c1cb5e73043dd1037f556d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e42102c1c07562853219ca5918803a27.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b68df477b3ee45ac0f725db00d465a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eefa44964db83759aff6fc8dd7ef8f28.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b1ec05e3cec27677ded7b4aecaa62d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b1ec05e3cec27677ded7b4aecaa62d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1241216f3c1cb5e73043dd1037f556d.png)
(2)设点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f3ffe7abc59e2f65d827c8eab8d36a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a498dc93f63f98990b8f63990d4fe2e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb6ede9761b5b90f8dc137708e1ee90f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1241216f3c1cb5e73043dd1037f556d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e52060a3cb5cde73c28264f4e08a3e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bdc0e53398b36c82db3808c68314621.png)
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4 . 为弘扬志愿者精神,某校举行“乐于助人”服务活动,现安排甲,乙等4人到三个不同地方参加活动,每个地方至少1人,若甲和乙不能去同一个地方,则不同的安排方式有______ 种.
您最近一年使用:0次
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5 . 垃圾分类是普惠民生的一项重要国策.垃圾分类不仅能够减少有害垃圾对环境的破坏,减少污染,同时也能够提高资源循环利用的效率.垃圾分类共分四类,即有害垃圾,厨余垃圾,可回收垃圾与其他垃圾.某校为了解学生对垃圾分类的了解程度,按照了解程度分为
等级和
等级,随机抽取了100名学生作为样本进行调查.已知样本中
等级的男生人数占总人数的
,两个等级的女生人数一样多,在样本中随机抽取1名学生,该生是
等级男生的概率为
.
(1)根据题意,完成下面的二维列联表.并根据小概率值
独立性检验,判断学生对垃圾分类的了解程度是否与性别有关?
附:
,其中
.
(2)为了进一步加强垃圾分类工作的宣传力度,学校特举办垃圾分类知识问答比赛活动.每局比赛由二人参加,主持人
和
轮流提问,先赢3局者获得第一名并结束比赛.甲,乙两人参加比赛,已知主持人
提问甲赢的概率为
,主持人
提问甲赢的概率为
,每局比赛互相独立,且每局都分输赢.抽签决定第一局由主持人
提问.
(i)求比赛只进行3局就结束的概率;
(ii)设
为结束比赛时甲赢的局数,求
的分布列和数学期望
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d33adb74906403b0b00fcbd9fa691d8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3ffd5c35bba71ea54c28622b6cf505d.png)
(1)根据题意,完成下面的二维列联表.并根据小概率值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ead9d6ff51996f3ebace6f212e11a9e4.png)
男生 | 女生 | |
![]() | ||
![]() |
![]() | 0.05 | 0.025 | 0.01 | 0.005 |
![]() | 3.841 | 5.024 | 6.635 | 7.879 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2187714e660234f0b72f2b47d3ea685a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
(2)为了进一步加强垃圾分类工作的宣传力度,学校特举办垃圾分类知识问答比赛活动.每局比赛由二人参加,主持人
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(i)求比赛只进行3局就结束的概率;
(ii)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bf3baba074e8aeb6f3ea117865bbd1b.png)
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