1 . 为了巩固拓展脱贫攻坚成果,不断提高群众的幸福感,政府积极引导某村农户因地制宜种植某种经济作物,该类经济作物的质量以其质量指标值来衡量,质量指标值越大表明质量越好.为了解该类经济作物在该村的种植效益,该村引进了甲、乙两个品种,现随机抽取了这两个不同品种的经济作物各100份(每份1千克)作为样本进行检测,检测结果如下表所示:(同一区间的数据取该区间的中点值作代表)
分别记甲、乙品种质量指标值的样本平均数为
和
,样本方差为
和
.
(1)现已求得
,
,试求
及
,并比较样本平均数与方差的大小;
(2)该经济作物按其质量指标值划分等级如下表:
现利用样本估计总体,试从样本利润平均数的角度分析该村村民种植哪个品种的经济作物获利更多.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/1/dbef0375-6f6f-4c48-904b-ab42de050a85.png?resizew=424)
分别记甲、乙品种质量指标值的样本平均数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfbe7f95b5d89f9409ec24536da9e826.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb525270c748eddaaecc4a549cca250e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfbc29b47b83fdc5368770b7b1acb439.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab1295cbd36fdc55a55b549aa2dd5887.png)
(1)现已求得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60a50e3a700a3dbed816e523511d2ad0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1b5af40032dc45a90198f9373cea5dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfbe7f95b5d89f9409ec24536da9e826.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab1295cbd36fdc55a55b549aa2dd5887.png)
(2)该经济作物按其质量指标值划分等级如下表:
质量指标值 | |||
作物等级 | 二级 | 一级 | 特级 |
利润(元/千克) | 10 | 20 | 50 |
现利用样本估计总体,试从样本利润平均数的角度分析该村村民种植哪个品种的经济作物获利更多.
您最近一年使用:0次
解题方法
2 . 为了了解大家对养宠物的看法,某单位对本单位450名员工(其中女职工有150人)进行了调查,发现女职工中支持养宠物的职工占
,若从男职工与女职工中各随机选取一名,至少有1名职工支持养宠物的概率为
.
(1)求该单位男职工支持养宠物的人数,并填写下列
列联表;
(2)依据小概率值
的独立性检验,能否认为该单位职工是否支持养宠物与性别有关?
附:
,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
(1)求该单位男职工支持养宠物的人数,并填写下列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
支持养宠物 | 不支持养宠物 | 合计 | |
男职工 | |||
女职工 | |||
合计 | 450 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ead9d6ff51996f3ebace6f212e11a9e4.png)
附:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2187714e660234f0b72f2b47d3ea685a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/356b05e46b10ee51c3e43546d73ec96c.png)
0.10 | 0.05 | 0.010 | 0.001 | |
2.706 | 3.841 | 6.635 | 10.828 |
您最近一年使用:0次
3 . 已知等差数列
的前n项和为
,且
.
(1)求
的通项公式;
(2)若
,求数列
的前n项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a16a21e64ee3172707d9933bf9d0d810.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e35b6e874e4eecad39c9cf469fa72b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次
解题方法
4 . 如图,在
中,
,
为
的中点,将
绕
所在的直线逆时针旋转至
形成如图所示的几何体
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/15/fec9202c-c8fa-48e5-9ef5-3d873f18658e.png?resizew=116)
(1)求几何体
的体积;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/866b81a8384cce4f24867baca2e6820c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51ff3fb840481d607d205e9dcd33ebd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/866b81a8384cce4f24867baca2e6820c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4686f39b38d5b90309ee73ed89a0640.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b94469fd19f40116e2dec334919d6586.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33a808d5b0143d90d09bccc8141371e1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/15/fec9202c-c8fa-48e5-9ef5-3d873f18658e.png?resizew=116)
(1)求几何体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b94469fd19f40116e2dec334919d6586.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4eb7e9ad5486cf1c5e506b20c5469e8.png)
您最近一年使用:0次
解题方法
5 . 已知
中,角
,
,
的对边长分别是
,
,
,
,且
.
(1)证明:
;
(2)若
,求
外接圆的面积
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](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/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5a611bebe78ba33770aec0fe46786a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6de1d395e6c48c0676a1488a299479d9.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3af83b4173f604bb5971b1597f9f01a.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6129fbf40a950fc8c516f0abaab21957.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
您最近一年使用:0次
6 . 已知在
中,角
所对的边分别为
,
.
(1)求A;
(2)若
的面积为
,点
是线段
上靠近A的三等分点,当
最小值时,求
.
![](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/8ce242bb75046665a1c5d5c64d587691.png)
(1)求A;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7cb903441d8e6b4448c3d5d7959d9d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
您最近一年使用:0次
解题方法
7 . 如图,矩形ABCD是圆柱
的一个轴截面,点E在圆O上,
,且
,
.
时,证明:平面
平面BDE;
(2)若直线AF与平面ODE所成角的正弦值为
,试求此时
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/192f4f9446c954a291f779d963f90257.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20c17e7cc178946d088d328634dfcb1d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2573d44bd027ab2e2fc2472c7852af8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e45886ddf14b971ee88af08a8a0fc30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73b3cf0f585938ede9eca890a6eb326d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1b9695c2226fd2093b0819e7f1d13f.png)
(2)若直线AF与平面ODE所成角的正弦值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e64e76a4c1e5934f51cdca2ffbc8313f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
您最近一年使用:0次
2023-05-05更新
|
614次组卷
|
4卷引用:河北省2023届高三模拟(一)数学试题
河北省2023届高三模拟(一)数学试题湖南省衡阳市衡南县2022-2023学年高二下学期期末数学试题(已下线)模块四 专题4 大题分类练 《空间向量与立体几何》拔高能力练【人教A版(2019)】专题01立体几何与空间向量(第一部分)-高二下学期名校期末好题汇编
解题方法
8 . 记△ABC的内角A,B,C的对边分别为
,
,
,已知![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7835f94169920faf8e04c623f41441ee.png)
.
(1)证明:
;
(2)若
,
,求△ABC的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7835f94169920faf8e04c623f41441ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d6c3e00a78921faf110ffb26d93bb2c.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02746ec8e4220d8b4a174d5e9a711ed2.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03837b3769eda7f0d3804cc5ad4a6d60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80fafa5beb70c80533bb17b31fb5416f.png)
您最近一年使用:0次
名校
解题方法
9 . 已知
,
,
分别为
内角
,
,
的对边,且
.
(1)求
的值;
(2)若
面积为
,求
边上的高
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](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/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d8d135b947c05c0be1c9dd8836f98d4.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3eabd5f3a86afe49dcd70571e2b96cfd.png)
您最近一年使用:0次
2023-05-03更新
|
1297次组卷
|
4卷引用:河北省2023届高三适应性考试数学试题
名校
解题方法
10 . 如图在平面四边形ABCD中,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/19/7e8b9812-ca26-42ea-8542-03490b1535d3.png?resizew=139)
(1)求边BC;
(2)若
,求四边形ABCD的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8e39bee1445161f91213c83b498b8ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efc6e4b936d7a800e839a30c3839574d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73c9491f900cc3cd4a80bd259c4717fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ba7ace6dc5b3f26ea674f64247484e1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/19/7e8b9812-ca26-42ea-8542-03490b1535d3.png?resizew=139)
(1)求边BC;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48e9140641e0195d64927dd3f23e7624.png)
您最近一年使用:0次
2023-04-18更新
|
1780次组卷
|
4卷引用:河北省部分学校2023届高三考前模拟演练数学试题