解题方法
1 . 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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解题方法
2 . 求证:
对任意实数
,
,
,
成立,等号成立的充分必要条件
.
提示:(1)以题目中的实数为坐标构造向量
,
,利用坐标计算出向量夹角
的余弦
再代入不等式
;
(2)为什么
?因为
.柯西不等式左右两边之差![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27fb555d58a0abf2991288f733622ec1.png)
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d115a39e93fabee911c86269199e13d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b715e7842b95f654f16056a7c7f2abe9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13423c094861baf4b759b7f3d8c3c226.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9490b6aa3c70b2d602ee98369f5aede.png)
提示:(1)以题目中的实数为坐标构造向量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e47852f72902319522dc20d17f7aec2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bf89b8b4b13539a33c5d7a17800f3e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aefd06c239145a2b6ae87a955aa51414.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed0431cd391637c69a538637ff22d2f8.png)
(2)为什么
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed0431cd391637c69a538637ff22d2f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6007f5e70739047bdf2d7a44d69cd134.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27fb555d58a0abf2991288f733622ec1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8caeecbfc6645fc3565c4ef2b94bcbd2.png)
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解题方法
3 . 如图,点A,B分别位于异面直线a,b上,过AB中点O的平面
与a,b都平行,M,N分别是a,b上异于A,B的另外两点,MN与
交于点P.求证:P是MN的中点.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
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4 . 仿照“用计算器求
的值”的方法,证明对数的换底公式.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed5faff5d08e2976e15f0cec988ced37.png)
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2023-10-08更新
|
36次组卷
|
3卷引用:北师大版(2019)必修第一册课本习题第四章2.2换底公式
21-22高二·江苏·课后作业
5 . 已知
,点
,
,直线
.求证:点P到直线l的距离等于
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a449474e7cf366add572ca32014a23e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7775aa57ca0e62216f3039ed88dceed0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f6d06b9a4d3a891ea7c986b1ab4e925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c75f0d9463771a3aba1865a9d9d398aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ac654a052f98d1ccb7fede1f122cec3.png)
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21-22高二·全国·课后作业
6 . 已知
是一个长方形,且M是
所在平面上任意一个点,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31bbd03b68460d0e9844d42e37a6d9bd.png)
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7 . 已知空间向量
,
,
,
,若存在实数组
和
,满足
,
,且
,求证:向量
,
,
共面.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb80eb942aafb194fadc473776f35b1d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/433b94c39737727e53468df419d8314a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb573cc0f30d5c32cdad1510793f0e7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b1bfbd2ef51eaeb6e686e27cc95638e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7aa7abe36a6aa866ac4d4e0ca83653cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c36e846eb9d6fbaadcb9b9b745779a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f0237dc4d7381893117a3aa4784afd5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ab74bb8aca5f0c69cbe968baf7eb6ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33bd24e647a626899a243a3f3984f90a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb80eb942aafb194fadc473776f35b1d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/433b94c39737727e53468df419d8314a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb573cc0f30d5c32cdad1510793f0e7b.png)
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2021-12-05更新
|
206次组卷
|
4卷引用:6.1空间向量及其运算
(已下线)6.1空间向量及其运算苏教版(2019) 选修第二册 名师导学 第六章 6.1.3 共面向量定理(已下线)专题一 专题1 空间向量与立体几何(1)(高二苏教)苏教版(2019)选择性必修第二册课本习题6.1 空间向量及其运算
21-22高一·湖南·课后作业
8 . 已知:
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e93622d238a10ef084d02a25e7d6e0a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f46c90b74747b4fbe7a10577158e998c.png)
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9 . 已知
,
,对任意的实数
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7326ea56be82bd616fec7e6aa3c884c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c624ba61a6885c1b81ec8d6c9307ecfe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad481cbfb67ac9cdbc0537f3de23b022.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/846ab1c77d4cd15dda12ed65a910ad40.png)
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20-21高二·全国·课后作业
10 . 如果
是等差数列,而且正整数
,
,
,
满足
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fb679318d0c9819b82e51a1750b502a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/095397b70a73758437ba2198b61fd79b.png)
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