1 . 任取
,直线
与圆
相交于
两点,则
的概率为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/429a7d5bbb7903b6fc9c5737b29c8543.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d33d6cda3499bda60140e621efc39fee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5f5d967ad135991b6075ee45df55643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c996a60d6b10871e88192728f21cee5d.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
名校
2 . 点
是正方体
的体对角线
上靠近点
的四等分点,在正方体随机取一点
,则点
满足
的概率为________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87cdc08e1c4a04a18d5ecea03393e36d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acbea970ac986a93a6c875f290a2ec20.png)
您最近一年使用:0次
2017-05-03更新
|
1049次组卷
|
4卷引用:江西省抚州市临川区第一中学2017届高三4月模拟检测数学(文)试题
2014·四川成都·一模
名校
解题方法
3 . 已知直线
与曲线
恰有两个不同的交点,记
的所有可能取值构成集合
,
是椭圆
上一动点,点
与点
关于直线
对称,记
的所有可能取值构成集合
,若随机从集合
中分别抽出一个元素
,则
的概率是___ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/490b32bc823fb54a07d7be750d0d626b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aef469c7b7cb9945b984222381b9c000.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8701e0cce437edc830438b4fe6277d89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d80a47fd46072cd717442cb378d431ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec391f08f1452fb3e0aebe7e12ba4fb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ab466aedd6e176088d8dee7bc3e3aaa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d7402fdeb91579061391e1845ed8d30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0d491ca1d69c14de489ec68aa280c97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fb43cf0211b9d86f94275fb78630510.png)
您最近一年使用:0次
2016-12-03更新
|
1081次组卷
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6卷引用:2015届四川省成都市高中毕业班摸底测试理科数学试卷
(已下线)2015届四川省成都市高中毕业班摸底测试理科数学试卷四川省成都市锦江区北京师范大学成都实验中学2019-2020学年高二上学期期中数学试题(已下线)专题10-3 概率小题基础-2022年高考数学毕业班二轮热点题型归纳与变式演练(全国通用)(已下线)专题10 概率与统计(文)【全国百强校】福建师范大学附属中学2018-2019学年高二上学期期末考试数学(理)试题湖南省湘潭一中2019-2020学年高三上学期11月月考理科数学试题
名校
4 . 某石化集团获得了某地深海油田区块的开采权,集团在该地区随机初步勘探了部分几口井,取得了地质资料.进入全面勘探时期后,集团按网络点来布置井位进行全面勘探,由于勘探一口井的费用很高,如果新设计的井位与原有井位重合或接近,便利用旧井的地质资料,不必打这口新井,以节约勘探费用,勘探初期数据资料见如表:
![](https://img.xkw.com/dksih/QBM/2017/9/10/1770866504433664/1771801974972416/STEM/73f778f7843445f1bed687d95844fbf4.png?resizew=532)
(参考公式和计算结果:
,
,
,
)
(1)1~6号旧井位置线性分布,借助前5组数据求得回归直线方程为
,求
的值,并估计
的预报值.
(2)现准备勘探新井
,若通过1,3,5,7号并计算出的
,
的值(
,
精确到0.01)相比于(1)中的
,
,值之差不超过10%,则使用位置最接近的已有旧井
,否则在新位置打开,请判断可否使用旧井?
(3)设出油量与勘探深度的比值
不低于20的勘探井称为优质井,那么在原有6口井中任意勘探4口井,求勘探优质井数
的分布列与数学期望.
![](https://img.xkw.com/dksih/QBM/2017/9/10/1770866504433664/1771801974972416/STEM/73f778f7843445f1bed687d95844fbf4.png?resizew=532)
(参考公式和计算结果:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9874c5d906442bd944d2ed717dba77f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8112f4d3ab5f8ec8405fe32fd181ce32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd152173762dc69f4a3f944178a02428.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19c33f47577bc27a3c44ddd3a390d512.png)
(1)1~6号旧井位置线性分布,借助前5组数据求得回归直线方程为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/324ea41abe9689065d399378c680fecb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
(2)现准备勘探新井
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e67a989651982be7e4269c32aae95c84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abc5505526d11946ca7d3a4421a9e08f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0032ca31e3cba58f973c6e75b907fb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abc5505526d11946ca7d3a4421a9e08f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0032ca31e3cba58f973c6e75b907fb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ff501dd16d9e3fd3dad9397a7a69f83.png)
(3)设出油量与勘探深度的比值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
您最近一年使用:0次
2017-09-11更新
|
895次组卷
|
3卷引用:2017-2018学年第一学期期末复习备考之精准复习模拟题高三年级(理)人教版数学试题(C卷)
(已下线)2017-2018学年第一学期期末复习备考之精准复习模拟题高三年级(理)人教版数学试题(C卷)广东省珠海一中等六校2018届高三第一次联考数学理试题福建省厦门外国语学校2018届高三下学期第一次(开学)考试数学(理)试题
5 . 某人种植一种经济作物,根据以往的年产量数据,得到年产量频率分布直方图如图所示,以各区间中点值作为该区间的年产量,得到平均年产量为455
,已知当年产量低于350
时,单位售价为20元/
,若当年产量不低于350
而低于550时,单位售价为15元/
,当年产量不低于550
时,单位售价为10元/
.
(1)求图中
的值;
(2)试估计年销售额的期望是多少?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a541551402a5fadca4831fe902e95c61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a541551402a5fadca4831fe902e95c61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a541551402a5fadca4831fe902e95c61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a541551402a5fadca4831fe902e95c61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a541551402a5fadca4831fe902e95c61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a541551402a5fadca4831fe902e95c61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a541551402a5fadca4831fe902e95c61.png)
(1)求图中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632244ea6931507f8656e1cc3437d392.png)
(2)试估计年销售额的期望是多少?
![](https://img.xkw.com/dksih/QBM/2018/3/2/1893490937143296/1894964417044480/STEM/8606f0a21ff4481cb17bc922cf0efe61.png?resizew=151)
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