1 . 在三棱锥
中,满足
,
,给出下列结论:
①
; ②若
是锐角,则
;
③若
是钝角,则
是钝角; ④若
且
,则
是锐角.
其中正确结论的序号为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9060f03b9ee41d70d135b1e1a8902ce9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35333abd7f02d663d15251bc5cbbf921.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4668ef024c694c0517c46af5e563495.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5695ba6ee3f7466b4b32c2e9340abf1.png)
③若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a72dfbf0138a611174c36ce077e0c47.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/149b1f4a7300425e6682e41d5f095377.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1f8fcbe6d923d1f5ba46a695756eb37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a72dfbf0138a611174c36ce077e0c47.png)
其中正确结论的序号为( )
A.①②④ | B.①④ | C.②③ | D.②④ |
您最近一年使用:0次
2 . 给出下列命题
①空间中所有的单位向量都相等;
②方向相反的两个向量是相反向量;
③若
满足
,且
同向,则
;
④零向量的方向是任意的;
⑤对于任意向量
,必有
.
其中正确命题的序号为( )
①空间中所有的单位向量都相等;
②方向相反的两个向量是相反向量;
③若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8ccba3b87a8a48ac3dd5f72d00bdb1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed22b2b145a4583668cef4c4b6c5f8b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8ccba3b87a8a48ac3dd5f72d00bdb1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06e9d440f180d0d8fb67b89d5c370158.png)
④零向量的方向是任意的;
⑤对于任意向量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8ccba3b87a8a48ac3dd5f72d00bdb1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbca1e8eb590d522e9be23be09170760.png)
其中正确命题的序号为( )
A.①②③ | B.⑤ | C.④⑤ | D.①⑤ |
您最近一年使用:0次
2021-11-27更新
|
618次组卷
|
2卷引用:福建省南平市浦城县2021-2022学年高二上学期期中考试数学试题