在空间四面体
中,
,
.求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b5f215a42c4b7078d8d65923eb9980e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70734a8e672376bb0bd1522e229f86a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b757f0c42ae5c9a2d6a4b19e5877b27.png)
23-24高二上·上海·课后作业 查看更多[1]
(已下线)复习题(三)
更新时间:2023-09-11 20:50:26
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相似题推荐
解答题-问答题
|
较易
(0.85)
【推荐1】构造始点、终点都是平行六面体
顶点的向量,使它与下列各式所表示的向量分别相等:
(1)
;
(2)
;
(3)
;
(4)
;
(5)
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3da8c338342e38c9aa3f274c053fd5b.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8701d25abd924708f064daac92402db9.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cdf86b332ad22ffe97848c99365c296.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cde9bb0173ea9f435b02b6f995c9772.png)
(4)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d8231a4020a7f315bc7be8edbe799a9.png)
(5)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66379428876b026dbe7bd2bf52d1d6d0.png)
![](https://img.xkw.com/dksih/QBM/2022/2/12/2914857448038400/2926282395254784/STEM/f7b281c0-07da-48db-825f-a5d4f5e290c8.png?resizew=233)
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
【推荐2】已知四面体OABC,M,N分别是棱OA,BC的中点,且
,
,
,用
,
,
表示向量
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/420ad6159fc091d6a5ffddf0676d2662.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68c2e7e9fd8519fd1c293cc577408263.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a40f8ef7e3af00c41f85a20578afdb57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a2f4b1178f68bd147d1a2a6acd04435.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c94075193c11fe43f2396cff5a485054.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d366d8fbb7258ee051f49977441e14a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a014dff8997c661055229de29c61cfc.png)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
【推荐1】如图,四面体OABC各棱的棱长都是1,D,E分别是OC,AB的中点,记
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/16/798d556e-3600-4ccb-ab4c-98717a72cb8a.png?resizew=174)
(1)用向量
表示向量
;
(2)求证
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe136ff8396ff6f80de6e616f290717.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1cae49aecae12a1aaaa29cb194a11bd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebca14060caa173dd7c922c560689064.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/16/798d556e-3600-4ccb-ab4c-98717a72cb8a.png?resizew=174)
(1)用向量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e3aab05482046ebd5b2487850d05273.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87833bb7b9bff8407e7ae4cfef9a9d15.png)
(2)求证
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32c38dfd14dde969702dff97ef2270f9.png)
您最近一年使用:0次
解答题-问答题
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较易
(0.85)
名校
解题方法
【推荐2】如图,二面角
的大小为
,四边形
与
均为正方形,
,
,记
.
(1)请用
表示
,并求
;
(2)求异面直线
与
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3e9d395e5501c87fec93dee44d24027.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e683b52b8ce8e8a15be7680f11b8b914.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9698abe469047f6ffbcbe1c816b97ef4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/15/1553d8d6-d4df-4950-80f8-11e332d2cce5.png?resizew=195)
(1)请用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e12e95f703ad30ab9a3d38376830989.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bad299e2782c072d27e1c54422cc8fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7592e81d3652ff9944b65a566aa24bef.png)
(2)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
您最近一年使用:0次