解题方法
1 . 如图,在平行六面体
中,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/15/86de3ee0-071b-4c8e-b591-625fa67ee6b3.png?resizew=167)
(1)求
的长;
(2)求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6539b62084f39afabcd9b93c2c562b7e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/15/86de3ee0-071b-4c8e-b591-625fa67ee6b3.png?resizew=167)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0aa142bb96af98b846997e681609739f.png)
您最近一年使用:0次
2 . 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
2021-11-18更新
|
393次组卷
|
3卷引用:山西省太原市2021-2022学年高二上学期期中质量监测数学试题
3 . 已知三棱柱
中,侧棱
底面
,记
,
,
.
![](https://img.xkw.com/dksih/QBM/2020/3/16/2420882788179968/2421575777787904/STEM/71f6e4ed48da42fe94d1d230e46472fb.png?resizew=172)
(1)用
表示
;
(2)若
,
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4827791eee92794c5324b24b86c83152.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febcf1295fc9f93c64876b128b1d3ddb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e46f9d7ad03ddb15f34255ca71a5445f.png)
![](https://img.xkw.com/dksih/QBM/2020/3/16/2420882788179968/2421575777787904/STEM/71f6e4ed48da42fe94d1d230e46472fb.png?resizew=172)
(1)用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96022a881e03e32d3483d997c3f170c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e610509e3f4fce4ca2e5ecefbe594bd8.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fa8345302e8036af33d4598282144d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e862713d078c4f06ec1f15ccd6f5a1f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09ba8eb4ac84cf535f80bd05b56f90fb.png)
您最近一年使用:0次