解题方法
1 . 用分层随机抽样从某校高一年级学生的数学期末成绩(满分100分,成绩都是整数)中抽取一个容量为100的样本,其中男生成绩数据40个,女生成绩数据60个,再将40个男生成绩样本数据分为6组: [40,50)、[50,60)、[60,70)、[70,80)、[80,90)、[90,100].绘制得到如图所示的频率分布直方图.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/6/22/5d98ca8d-fd49-4a68-9d05-1e3863845c30.png?resizew=239)
(1)求a的值;
(2)若在区间[40,50)和[90,100]内的两组男生成绩样本数据中,随机抽取两个进行调查,求调查对象来自不同分组的概率:
(3)已知男生成绩样本数据的平均数和方差分别为71和187.75,女生成绩样本数据的平均数和方差分别为73.5和119,求总样本的平均数和方差.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/6/22/5d98ca8d-fd49-4a68-9d05-1e3863845c30.png?resizew=239)
(1)求a的值;
(2)若在区间[40,50)和[90,100]内的两组男生成绩样本数据中,随机抽取两个进行调查,求调查对象来自不同分组的概率:
(3)已知男生成绩样本数据的平均数和方差分别为71和187.75,女生成绩样本数据的平均数和方差分别为73.5和119,求总样本的平均数和方差.
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解题方法
2 . “用一个不垂直于圆锥的轴的平面截圆锥,当圆锥的轴与截面所成的角不同时,可以得到不同的截口曲线”,利用这个原理,小强在家里用两个射灯(射出的光锥视为圆锥)在墙上投影出两个相同的椭圆(图1),光锥的一条母线恰好与墙面垂直.图2是一个射灯投影的直观图,圆锥
的轴截面
是等边三角形,椭圆
所在平面为
,则椭圆
的离心率为______________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef49a3ca580a144cc65a609c167facc1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/745e0525a41fe2e2a7739c75a942290b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f919bd3dde10dbbc076f7ec5149699.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f4b27f503ce08bc7851006a98f9ce32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f919bd3dde10dbbc076f7ec5149699.png)
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3 . 如图,在正四棱锥
中,
为底面
的中心.
,
,求正四棱锥的体积;
(2)若
,
为
的中点, 求直线
与平面
所成角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/574dc284fb9e74d65cf0c79a978d65de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97be8206012b8d5b1402dfa5e9761196.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bd50cf631e459b58b180cdf2f57844c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87827211113fd8f5d1afd793927222d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46e2da608b66c9aee03e2503388ba4fd.png)
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4 . 已知椭圆
的左、右顶点分别为
、
,且椭圆
经过点
.
(1)求
的值,并求经过点
且与圆
相切的直线方程;
(2)设
为椭圆
上的一个异于
、
的动点,直线
、
分别与直线
相交于
、
两点,求
的最小值:
(3)已知椭圆
上有不同的两点
、
,且直线
不与坐标轴垂直,设直线
、
的斜率分别为
、
,求证:“
”是“直线
经过定点
”的充要条件.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0f1e4548f62c6e3f124656c76ee64d0.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/4bcd8ee2d8367c167d6ae0abc741b6b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c16dcb66cd0d298f31f4f9c7e3a5fdcb.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b68df477b3ee45ac0f725db00d465a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f240cccaf24af8a796abb95cb42be52e.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bcd8ee2d8367c167d6ae0abc741b6b8.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/a6da2235c42867f9a79007c3fc83fec9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca3bd41676f6b69acac00a292fe134cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f23d29646155e27b172ecdf263e2d702.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/a3d87446c9ef0230285d9b08127fce5c.png)
(3)已知椭圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bcd8ee2d8367c167d6ae0abc741b6b8.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/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b66a5b7813e902306477f91f9f4084cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/279563c3c055777ce1aa369a2ef54aed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6defc43285a40f7ccb74c1cc04265eba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/423b7ae39db552e60ee8b1d27312306f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66de27301ae08a4154ed37bb4a261b6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff32d26c8d44f5fb4813a19c1030a9f5.png)
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解题方法
5 . 设
是一个无穷数列
的前
项和,若一个数列满足对任意的正整数
,不等式
恒成立,则称数列
为和谐数列.关于命题:①若等差数列
为和谐数列,则
一定存在最小值;②若
的首项小于零,则一定存在公比为负数的一个等比数列为和谐数列.下列判断正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edefd533852c96d0d8047c859d4bc458.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](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/83cf38189d5cbf627d2b82ac0eb76006.png)
A.①和②都为真命题 | B.①和②都为假命题 |
C.①为真命题,②为假命题 | D.①为假命题,②为真命题 |
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解题方法
6 . 设
.
(1)若
,求函数
的图象在
处的切线方程;
(2)若
在
上恒成立,求实数
的取值范围;
(3)若函数
存在两个极值点
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab44240a0cb09a1b9f5966c63fa290f3.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b384412acba251d87902ab928902f16.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e9c599e8d420006448905acec2b8234.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae386699086599e0bcb0fbe59cffd9fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(3)若函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fd785bc48778543268feeca30728c34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03ca13a93b5f401c0d39ba52b0cffcb0.png)
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7 . 在空间直角坐标系
中一点
关于坐标平面
的对称点
的坐标为___________
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5e336d6ca2cae3d6e6c3810d7e521a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d503be9fe90bbd8ca3ee97deabce901.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ef1e8a88d934eca5399decc64fdbd43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cee6765a83140d745a6de4c85d9b6b50.png)
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解题方法
8 . 已知数列
各项均为正数,且
,记其前
项和为
.
(1)若数列
为等差数列,
,求数列
的通项公式:
(2)若数列
为等比数列,
,求满足
时
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(1)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1dfe5b322577f02fd19caab8cf20170.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e31a059268c7801f786e93a76d65b68f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8bedfcdf5e750f5451e0e5183c0d80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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9 . 直线
与直线
的夹角为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37a8c6b29aa13470b830e554ef83c591.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0b7340df77db83f1282ecc3008ca6f5.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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10 . 若
则正整数n的值为_______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37a103e3a2e0be52d74f976230ab72b2.png)
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