解题方法
1 . 假设通过简单随机抽样得到
和
的抽样数据列联表,
课本中给出
统计量计算公式如下:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e96c085aa9f50132a4c676d38423f64.png)
此处我们把
列联表中的
,
,
,
称为观察频数,记作
,(例如
,
),
把
,
,
,
称为期望频数,记作
,
即第i行的频数和乘以第j列的频数和与频数总和的商.(例如
,
).则我们可以将卡方统计量的计算公式写成以下更为一般的形式:
(Σ表示对后面的代数式求和)
根据以上信息,假设一项研究旨在分析不同教学方法对学生数学成绩的影响。研究中采用了三种不同的教学方法:传统方法、在线学习和互动式学习。学生根据他们的成绩被分为三个级别:低、中、高,用频率估计概率。研究结果如下表所示:
(1)已知在“传统方法”中,参加数学兴趣小组的同学按照成绩“低”、“中”、“高”的分别占对应人数的
、
、
,求“传统方法”中参加数学兴趣小组同学的概率.
(2)(i)求
,
;
(ii)依据小概率值
的独立性检验,分析这三种教学方法对学生数学成绩影响是否存在显著差异.
参考数据:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
合计 | |||
合计 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/953e89f7e797bf8fe9ff31e0d2f66728.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e96c085aa9f50132a4c676d38423f64.png)
此处我们把
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.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/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2afa9d81956a0fd618fd92e3b750e73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2da67153d6ad625ae931c262eba879b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cebc26a56f0ac066f261f570264b0b7d.png)
把
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7abc2d18f6c594a766547076789b62c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a149141c81a753bb8b97a53f04c2880.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75d62574362e968fbff2ca3624d221ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/839070d7c20eab9731e9f5f5055d3e09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d97229672528bcfdfa5fc59e1f2adf1.png)
即第i行的频数和乘以第j列的频数和与频数总和的商.(例如
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93aa96edeffc11966ad12ef8b9b7a4e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b24948f79d91b04c118661d8d24b3aa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65b1549b8ac64f2b003255b4ce798dac.png)
根据以上信息,假设一项研究旨在分析不同教学方法对学生数学成绩的影响。研究中采用了三种不同的教学方法:传统方法、在线学习和互动式学习。学生根据他们的成绩被分为三个级别:低、中、高,用频率估计概率。研究结果如下表所示:
教学方法\成绩级别 | 低 | 中 | 高 | 总计 |
传统方法 | 20 | 30 | 50 | 100 |
在线学习 | 35 | 45 | 20 | 100 |
互动式学习 | 25 | 15 | 60 | 100 |
总计 | 80 | 90 | 130 | 300 |
(1)已知在“传统方法”中,参加数学兴趣小组的同学按照成绩“低”、“中”、“高”的分别占对应人数的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3ffd5c35bba71ea54c28622b6cf505d.png)
(2)(i)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd6995e31e99952401de7dd3aee2f85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d48d9f996f77a4e3821fd7245a30a1f9.png)
(ii)依据小概率值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ead9d6ff51996f3ebace6f212e11a9e4.png)
参考数据:
0.100 | 0.050 | 0.025 | 0.010 | 0.005 | |
7.78 | 9.49 | 11.14 | 13.28 | 14.86 |
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2 . 生物钟(昼夜节律)是生物体内部的一个调节系统,控制着生物的日常生理活动.研究显示,人体的某些荷尔蒙(如皮质醇)在一天中的分泌量会随着时间的不同而发生变化,从而影响人的活力和认知能力.假设人体某荷尔蒙的分泌量
(单位:
)与一天中的时间
(单位:小时,以午夜0点为起点)的关系可以通过以下分段函数来描述:
●在夜间
,荷尔蒙分泌量保持在较低水平,可以近似为常数
.
●在早晨
,随着人醒来和太阳升起,荷尔蒙分泌量线性 增加,其关系为
,当
时,分泌量达到最大值![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1e7f77c4297fbed97c37ebf492b53c.png)
●在下午和晚上
,荷尔蒙分泌量逐渐降低,可以用指数衰减模型描述,即
.
已知午夜时荷尔蒙分泌量为
,峰值分泌量为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a97437b6ca3463ab7a0017eb660ee6f.png)
(1)求参数
,
和
的值以及函数
的解析式;
(2)求该同学一天内荷尔蒙分泌量不少于
的时长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26e91406484c332ac8fc96a54c7e187b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e3fac814e1c648fd71c01e110d5c1dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
●在夜间
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25e9155ddb70e05907745867d4f100ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/082a96bf5a330006dd5c1af649707770.png)
●在早晨
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/641ec9ed04accc9a3923000686a3667d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a80f648e64e65a72d99e4461d6f5d541.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57127a1bae23a6d3a266ffae18601f62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1e7f77c4297fbed97c37ebf492b53c.png)
●在下午和晚上
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a03f8193f6bc7b48296312328d668e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82fd9f11c2c8ec2d514cb87ea572c61c.png)
已知午夜时荷尔蒙分泌量为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b4fabe8266a844bdd40b88525d38a8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a97437b6ca3463ab7a0017eb660ee6f.png)
(1)求参数
![](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/26e91406484c332ac8fc96a54c7e187b.png)
(2)求该同学一天内荷尔蒙分泌量不少于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87d26a08806fc86a287073b740917fc2.png)
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3 . 考虑两个变量
和
的样本数据集,其样本相关系数
通过以下公式给出:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9b7bf5d6241cae545e97666f79cb456.png)
其中,
和
分别是
和
的第i个样本值,
和
分别是
和
的样本均值.下列关于样本相关系数公式各部分的陈述正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f5f03b913fe4ea84abed8538758cfc2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9b7bf5d6241cae545e97666f79cb456.png)
其中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97ea8f47d8d8d9e1832d52b1c7425450.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4de122ae929b1acaff321dec137622ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c85481cd7e94130ef3aa05b4a39e79cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/923d80da4a6cb5f102be334006d875a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
A.分母中的![]() ![]() ![]() ![]() |
B.分子部分![]() |
C.样本相关系数的值越接近于0,表示![]() ![]() |
D.通过对分子部分进行标准化处理,样本相关系数能够消除变量的度量单位的影响,使得不同数据集之间的相关性能够进行直接比较. |
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4 . (1)求方程
的根,并判断它们是否共轭;
(2)若复数满足
,求
的范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9075fb6184add4c2b3be66bab48ec5.png)
(2)若复数满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/839ba7c0f1fc30151d18a2e337951dd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6371658485ad1afc0d054c1b5e70ee5f.png)
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5 . 如图,2024年元宵节在浙江桐乡凤凰湖举行“放孔明灯”活动.为了测量孔明灯的高度,在地上测量了一根长为200米的基线
,在点
处测量这个孔明灯的仰角为
,在
处测量这个孔明灯的仰角为
,在基线
上靠近
的四等分点处有一点
,在
处测量这个孔明灯的仰角为
,则这个孔明灯的高度![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6a548e8a2e2205f2faa87e25180a083.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6ec007c9c7ce7e13af3ca8b84c64ef6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcc0c3626d9b2c9cc92403e99e727912.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32c0b52fdca650c96f803556a514b08f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6a548e8a2e2205f2faa87e25180a083.png)
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解题方法
6 . 已知
,且
,点P的轨迹为C.
(1)求C的方程;
(2)直线l:
与C相交于M,N两点,第一象限上点T在轨迹C上.
(ⅰ)若
是等边三角形,求实数k的值;
(ⅱ)若
,求
面积的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a8440227efdc641333e2b39c8497a6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55388e2f910665e103b168af61c1fa76.png)
(1)求C的方程;
(2)直线l:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac02a054bd0771a56987af33454baaea.png)
(ⅰ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6bf66a5f30d94390f59c6a3d1ae6c46.png)
(ⅱ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e849753c1b4bbab8327c5ade6cc2469.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6bf66a5f30d94390f59c6a3d1ae6c46.png)
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7 . 已知复数
,
是方程
的解,复平面内表示
的点A在第四象限,O是原点.
(1)点A关于虚轴的对称点为点B,求向量
对应的复数;
(2)将复数
对应的向量
绕原点逆时针旋转
得到向量
,
对应的复数为
,求
的值;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af68f652b4c13657ffddf3c9e7eb262b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa224ed9be8766a4d0b5138bd57de0f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfd94ededc533b2bd356576d94e1ea6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af68f652b4c13657ffddf3c9e7eb262b.png)
(1)点A关于虚轴的对称点为点B,求向量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fc9656d8286c4d6fa309d6ae347c89e.png)
(2)将复数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa224ed9be8766a4d0b5138bd57de0f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef8337706c550bc095d7a2bd872221a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1ad72d7565699d1ebb741eb0ce12bac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f28b09c6074898b0bf992928336eb5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f28b09c6074898b0bf992928336eb5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a67a742d2a43e907fb1c3a1bdf1d6a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aeaaa82e920b2caa9d11b9071fab385a.png)
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8 . 平行四边形ABCD中
,且
,AB、CD的中点分别为E、F,将
沿DE向上翻折得到
,使P在面BCDE上的投影在四边形BCDE内,且P到面BCDE的距离为
,连接PC、PF、EF、PB,下列结论正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f80f51c31583fea58fde645474d60b8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cff7399ecc698e2fb415147c96d0d03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1174142f3bba761585b6bc2653009b36.png)
A.![]() |
B.![]() |
C.三棱锥![]() ![]() |
D.点Q在线段PE上运动,则![]() ![]() |
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解题方法
9 . 若函数
有且仅有一个极值点
,函数
有且仅有一个极值点
,且
,则称
与
具有性质
.
(1)函数
与
是否具有性质
?并说明理由.
(2)已知函数
与
具有性质
.
(i)求
的取值范围;
(ii)证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d0112af71e654cc86c8d5056fdbb2a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/861433f0c552c5bef8d8c03682d91858.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7091d529281abff275ef19b9197445a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d0112af71e654cc86c8d5056fdbb2a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/861433f0c552c5bef8d8c03682d91858.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d77fbccb3ae7f7836d16dfb4952e4cc.png)
(1)函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47d2a4a953934dcaf87f2ce64c6dab4e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0482361cb97998139441fe0deb23578e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a9d58d2cef0d86281fdde5895a129a6.png)
(2)已知函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b00477b17f5248a7301290d260a6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e5eef1c41c5ed94a4944e062bcfeeeb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f36ea881341f274252964bc3a9fc5693.png)
(i)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(ii)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/926521541bf1c18ac229afc5ec2d9b51.png)
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10 . 小明进行足球射门训练,已知小明每次将球射入球门的概率为0.5.
(1)若小明共练习4次,求在射入2次的条件下,第一次没有射入的概率;
(2)若小明进行两组练习,第一组射球门2次,射入
次,第二组射球门3次,射入
次,求
.
(1)若小明共练习4次,求在射入2次的条件下,第一次没有射入的概率;
(2)若小明进行两组练习,第一组射球门2次,射入
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/096b1ece1dcd29c59a46a4b3e02cb548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5031a3a951c4a1d1c5e9f80a5e26513.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8aa586c1ddb027aa28b40f5af8089d3.png)
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