已知正四面体
中,
分别是线段
,
的中点,
是线段
上的动点(含端点).
与平面
所成的角为
,二面角
的平面角为
,二面角
的平面角为
,则( )
![](https://img.xkw.com/dksih/QBM/2020/4/20/2445448635613184/2445642378665984/STEM/56c8687d0f6344fc8fbdaa055e527620.png?resizew=129)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25f64fa38725c136504f723019a18dc5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/432b602bbaf82a4a40091ecfc8a8ffb0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e93fa313adc4ac7608ba9449fd755212.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca6d1c5eace748465b2dad5065f5111c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e8d4017e1a37acb0c8e00508be472b2.png)
![](https://img.xkw.com/dksih/QBM/2020/4/20/2445448635613184/2445642378665984/STEM/56c8687d0f6344fc8fbdaa055e527620.png?resizew=129)
A.![]() | B.![]() | C.![]() | D.![]() |
更新时间:2020-04-20 17:35:04
|
相似题推荐
单选题
|
较易
(0.85)
解题方法
【推荐1】已知
是三条不重合的直线,
是三个不重合的平面,给出下列四个命题:
①若
,则
;
②若直线
与平面
所成的角相等,则
;
③存在异面直线
,使得
,
,
,则
;
④若
,则
;
其中正确命题的个数是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ead7f004a93707d658819c75a89dfa0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61ba63ad02b1d5af2982fac3d91eb15c.png)
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfded4b317af0ba9368ebcedd306b427.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5986f2991d45fbf3578f08f27d9fd7e.png)
②若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/280860dd039e1305a5ccc455f63e8223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a93a52c2b943e4c70ace99ed802d2b5.png)
③存在异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/280860dd039e1305a5ccc455f63e8223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4042f9c51f83e3367d496e851735d7f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/808c6d37467a5c995d71e49408503927.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f4ded3c4bc7a2212f2a0eb5f9753de5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35f747152f006301e03b643afb80195c.png)
④若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ab5b905ff4ecca2d1f9ff74a2192c30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a93a52c2b943e4c70ace99ed802d2b5.png)
其中正确命题的个数是
A.1 | B.2 | C.3 | D.4 |
您最近一年使用:0次
单选题
|
较易
(0.85)
名校
【推荐2】若一条直线于一个平面成
角,则这条直线与这个平面内经过斜足的直线所成角中最大角等于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7115234b8a2ef6e324dc9f71a44e9cc2.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
单选题
|
较易
(0.85)
【推荐1】两二面角的两个半平面分别垂直,则这两个二面角的平面角( )
A.相等 | B.互补 | C.相等或互补 | D.不确定 |
您最近一年使用:0次
单选题
|
较易
(0.85)
名校
解题方法
【推荐2】已知四面体
中,
,
,
,则二面角
的余弦值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c4cb73e9d976cbfe9c590044fa69dd5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5aac0c43f94c561bacc7c9ac666f583.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd29cc627d76412c236aac6b29fa0fdf.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次