1 . 长度为6的线段,设线段中点为G,线段
的两个端点P和Q分别在x轴和y轴上滑动.
(1)求点G的轨迹方程;
(2)设点G的轨迹与x轴交点分别为A,B(A点在左),与y轴交点分别为C,D(C点在上),设H为第一象限内点G的轨迹上的动点,直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca14f6100d829f197a5dac5197bbe0b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6655e2fa64a32cd12fe0279afd65d73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92002afa0b414eae387a91207c629398.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
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2 . 总结空间线面的垂直关系,怎样判定这些关系?它们之间有什么联系?如何证明性质定理?
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3 . 求证:斜棱柱的侧面积等于它的直截面(垂直于侧棱并与每条侧棱都相交的截面)的周长与侧棱长的乘积.
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4 . 已知点
,
,
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0929421a6188c3122442866b0b85a5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f55d12701014cf53071093e8739d089b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6481e5ef435b6ad8ecac30175f6871bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
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5 . 设O为坐标原点,点M,N在抛物线
上,且
.
(1)证明:直线
过定点;
(2)设C在点M,N处的切线相交于点P,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc7ad3432ac96b0a38beaa7f2edc3499.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/964889aaf14b9ef1837a988c048788e4.png)
(1)证明:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
(2)设C在点M,N处的切线相交于点P,求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db3cbb23e45970803a178f2bc7806156.png)
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6 . 设X是一个随机变量,c是常数.求证:X+c的方差与X的方差相等.
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23-24高二上·上海·课后作业
7 . 袋中装有m个红球和n个白球,且
.这些红球和白球的大小及质地都相同.从袋中同时任取2个球,若2个球都是红球的取法总数是2个球颜色不同的取法总数的整数倍,求证:m必为奇数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6831396108be8bf5573e30b78e745bb3.png)
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23-24高二上·上海·课后作业
8 . 证明:在抽签的时候,抽到好签的概率与抽签顺序没有关系.
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23-24高二上·上海·课后作业
9 . 请指出下列各题用数学归纳法证明过程中的错误.
(1)设
为正整数,求证:
.
证明:假设当
(
为正整数)时等式成立,即有
.
那么当
时,就有![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b265260b1c40af006ba6f66a11ed576.png)
.因此,对于任何正整数
等式都成立.
(2)设
为正整数,求证:
.
证明:①当
时,左边
,右边
,等式成立.
②假设当
(
,
为正整数)时,等式成立,即有
,
那么当
时,由等比数列求和公式,就有
,等式也成立.
根据(1)和(2),由数学归纳法可以断定
对任何正整数
都成立.
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b502d9c57239d9f42fdf849878018061.png)
证明:假设当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ef7ca2b3e8061384501f668e59696a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d8963d68c930f5b28cc8b92c43d469b.png)
那么当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63ba21f3d0cfc86d40e2e06446623ce0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b265260b1c40af006ba6f66a11ed576.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced66f7e147b6276e1ce9e2b67510141.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8883d7d43d3f61a771d16537c52ac451.png)
证明:①当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c87b351f16728b0023fd63678f8103c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f90bae886c8ab958aa4c693bf8e0627d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f90bae886c8ab958aa4c693bf8e0627d.png)
②假设当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ef7ca2b3e8061384501f668e59696a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2397df3279607612ea3cbef101ee0bf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a439aebc27b99718f09e1dff2649482f.png)
那么当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63ba21f3d0cfc86d40e2e06446623ce0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b838d781d5ce98ddcc08af86c1f27ae.png)
根据(1)和(2),由数学归纳法可以断定
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8883d7d43d3f61a771d16537c52ac451.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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