名校
解题方法
1 . 在正方体
中,M为
的中点,N为
的中点,则异面直线
与
的夹角的余弦值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83c09eec4e14a861af83d7828797d176.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f6f93171329d508d491143b9d71f7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9932b14d1f7f381263281a50100c27b.png)
A.![]() | B.![]() | C.![]() | D.前三个答案都不对 |
您最近一年使用:0次
2023-07-31更新
|
248次组卷
|
4卷引用:2018年北京大学博雅计划数学试题
解题方法
2 . 如图①,
是梯形
的高,
,现将梯形
沿
折起成如图②的四棱锥
,使得
.点E是线段
上一动点.
![](https://img.xkw.com/dksih/QBM/2023/4/6/3210683025580032/3210718068342784/STEM/25a581f915434858ab85dbca14e4bc5b.png?resizew=463)
(1)判断
和
是否可能垂直,并说明理由.
(2)当
时,求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afd06501e333d6501c171640ccf05414.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b744576b325f894cc71ffa1aa4d38b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9641d01140939c44450bf39773272af6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/2023/4/6/3210683025580032/3210718068342784/STEM/25a581f915434858ab85dbca14e4bc5b.png?resizew=463)
(1)判断
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3b17ba2410af31808093fc780fd2438.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fc7991ea17d54ff5f4445ac5699463.png)
您最近一年使用:0次
解题方法
3 . 设
为平面,且
.若
与
所成的二面角为
,l与
所成角为
,则
与
所成的锐二面角为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61ba63ad02b1d5af2982fac3d91eb15c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d8a1d1c06fb34527b3f09a150805ef0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f435efcc7869eec21bdba1ed81dc3f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f435efcc7869eec21bdba1ed81dc3f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6b86c22b670a8e9f3896f9e8883fbbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f435efcc7869eec21bdba1ed81dc3f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
解题方法
4 . 在三棱锥
中,底面
为等边三角形,
平面
,且
,M,N分别为
的中点,则异面直线
与
所成角的正弦值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45fbffb9e2c7fa7c5006cde8da0cabe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07154bbdb201dd7858cccbc71f053b00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5881068127a39caf319492b4177204f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c8ffe24cf9f327aeb241225ab15ab1a.png)
A.![]() | B.![]() | C.![]() | D.前三个答案都不对 |
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5 . 空间图形
的体积为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/344cb2a08769d8cc7e350b2e7573e6c1.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次