1 . 我们知道,在平面内取定单位正交基底建立坐标系后,任意一个平面向量,都可以用二元有序实数对
表示.平面向量又称为二维向量.一般地,n元有序实数组
称为n维向量,它是二维向量的推广.类似二维向量,对于n维向量,也可定义两个向量的数量积、向量的长度(模)等:设
,
,则
;
.已知向量
满足
,向量
满足
.
(1)求
的值;
(2)若
,其中
,当
且
时,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39c2af42141367e6e9ff0296c31daa7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62b3b354facacd72bc68da6ac07be453.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a48d974578eb15ca117e0cb1b59788d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99aa60676891adca75eac086182a15c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2581496116ddfba6dd03722fd771d5a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5babafd9f4e5c3c222ba25a3de66794.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a48d974578eb15ca117e0cb1b59788d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7cb2f5c0569962cd7c1026f388cb661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99aa60676891adca75eac086182a15c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4492fb816272cd60cf3456c6a064020e.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efa3e5481ce1f11ea4cb1d1ddc71413.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/301fa5679316c282923735aff9285559.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95ac252e9126ab540c0102b941f0ee42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36b98ef143f8159f3a7dafa1fd2f2370.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74cac554f22f3655ef6691b2ef821eac.png)
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2 . 对于任意不为0的实数
定义一种新运算“#”:①
;②
,则关于
的方程
的根为__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccc9b449710062494286a01537ecdc00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3d785aaa5c1be4b5728cf56b4727d7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/820023f3de39dffe868be95757ce76d2.png)
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解题方法
3 . 法国数学家弗朗索瓦·韦达发现了一元二次方程的根与系数之间的关系,将其推广到高次方程,并在其著作《论方程的识别与订正》中正式发表,后来人们把这个关系称为韦达定理,即如果
是关于x的实系数一元n次方程
在复数集C内的n个根,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/988acbe8533ef50c899650a057717cf5.png)
试运用韦达定理解决下列问题:
(1)已知
,
,
,求
的最小值;
(2)已知
,关于x的方程
有三个实数根,其中至少有一个实效根在区间
内,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44258e924e42ec263b5236499252d4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f44bf708f38a916de0572d8ef1cf45a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/988acbe8533ef50c899650a057717cf5.png)
试运用韦达定理解决下列问题:
(1)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3eb9b6fe8959ae9e71e857b6d6fed49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/751e274e9107d780c39ba9c49d6daefb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/460b68eaa42bc8929edf81e21ad0bca0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bc2818de1c0d7d347718672b0bcec32.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73254f32b6da29ecc32df2e9f87a4c97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a070d41a05c5193153ae18e0235a492.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4a90cfdbfa05577b6ec0b22739e7c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/754826457671db8939098215943e656a.png)
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解题方法
4 . 已知八面体
由两个正四棱锥
和
组成.若该八面体的外接球半径为3,且平面
平面
,则该八面体的体积为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73cbd9eb22f75ad5304d8491b314a9a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55c6caa0455442437177ab9b995df37b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
A.28 | B.32 | C.36 | D.40 |
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解题方法
5 . 正方体
中,
,P在正方形
内(包括边界),下列结论正确的有( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
A.若![]() ![]() |
B.三棱锥![]() ![]() |
C.若Q为正方形![]() ![]() ![]() |
D.![]() |
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2024-06-02更新
|
654次组卷
|
3卷引用:专题4 立体几何中的动态问题【讲】
2024高三·全国·专题练习
6 . 设
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29bb95f1d117fcd5ae3250a1d74bc15f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e73f68b930b29a42fd8860eefe741d10.png)
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名校
解题方法
7 . 设
为某正方体的一条体对角线,
为该正方体的各顶点与各棱中点所构成的点集,若从
中任选两点连成线段,则与
垂直的线段数目是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
A.12 | B.21 | C.27 | D.33 |
您最近一年使用:0次
2024-05-31更新
|
363次组卷
|
3卷引用:计数原理与二项式定理-综合测试卷B卷
8 . 北宋科学家沈括在《梦溪笔谈》中记载了“隙积术”,提出长方台形垛积的一般求和公式.如图,由大小相同的小球堆成的一个长方台形垛积的第一层有
个小球,第二层有
个小球,第三层有
个小球……依此类推,最底层有
个小球,共有
层,由“隙积术”可得 这 些 小 球 的 总 个 数 为
若由小球堆成的某个长方台形垛积共8层,小球总个数为240,则该垛积的第一层的小球个数为( )
![](https://img.xkw.com/dksih/QBM/editorImg/2024/5/9/08b5b114-291b-48fd-96e1-14b11208b7d0.png?resizew=167)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d993cf0a090de3b01f1dda52c6fdc9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28b4f6054ca644083ecfa85ed1bb7592.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b939f6c148a4e5fae83668aaa627836.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/023fc87942a6821ca78d8cae08917352.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d34cf59fcb503ce674a118159af9244c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/5/9/08b5b114-291b-48fd-96e1-14b11208b7d0.png?resizew=167)
A.1 | B.2 | C.3 | D.4 |
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解题方法
9 . 如图(1),正三棱柱
,将其上底面ABC绕
的中心逆时针旋转
,
,分别连接
得到如图(2)的八面体
,依次连接该八面体侧棱
的中点分别为M,N,P,Q,R,S,
(ⅰ)求证:
共面;
(ⅱ)求多边形
的面积;
(2)求该八面体体积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a3a008a5ce2f3e0d93bf1b31f1e941d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1b73c7e51c2fbe79faa78e5287d2ccc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ff5cc57686ee7429fee0907651083c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78a40d2cf43fce0c99dff3470d554eb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ff5cc57686ee7429fee0907651083c4.png)
(ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8ae231960760617a585b8478185d8ac.png)
(ⅱ)求多边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac3662c929bd88085eb96dd4797482de.png)
(2)求该八面体体积的最大值.
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解题方法
10 . 正方体
的棱长为
,
是正方体表面及其内部一点,下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
A.若![]() ![]() ![]() |
B.若![]() ![]() ![]() ![]() |
C.若![]() ![]() ![]() |
D.若![]() ![]() |
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