已知两个向量
,且
,则
的值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ace56e9effde74cc8ff804246e54073.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84e0eb433065c91c26548e916ba31a36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
A.![]() | B.![]() | C.![]() | D.![]() |
更新时间:2024-05-27 23:51:36
|
相似题推荐
单选题
|
较易
(0.85)
解题方法
【推荐1】设向量
与
夹角的余弦值为
,且
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a92e6eba8dab638fd66831cd3a0b6d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/427fa45527d0ce469bfd060bf6f991f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f1dd362f843e640ce551ad1787c9873.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f3fcfb99b31a1f4d482d395f7456a67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/335c393201c9e2fd1657137de3cfc6c2.png)
A.![]() | B.![]() | C.3 | D.-3 |
您最近一年使用:0次
单选题
|
较易
(0.85)
名校
【推荐1】下列命题:①若向量
均为单位向量,则
;
②若向量
满足![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a2f4b1178f68bd147d1a2a6acd04435.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e37e60777a4cfa57422870eec6058a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a2f4b1178f68bd147d1a2a6acd04435.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
;
③向量
的充要条件是
且
;
④
是不共线的四点,则“
”是“四边形
为平行四边形”的充要条件;
⑤若向量
满足
,则
.
其中,真命题的个数是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b172cf8d898883d82e973f28c3c3a3e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/778542d99ab19e2ecc0c7ef75161f133.png)
②若向量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae951e0bb5a2a406f1572fc1e4964265.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a2f4b1178f68bd147d1a2a6acd04435.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e37e60777a4cfa57422870eec6058a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d366d8fbb7258ee051f49977441e14a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a2f4b1178f68bd147d1a2a6acd04435.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d366d8fbb7258ee051f49977441e14a2.png)
③向量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/778542d99ab19e2ecc0c7ef75161f133.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35e9616e55c8107822a14b0c9be94497.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1afa49dbaa99a0d7a7a6d18b3fe42091.png)
④
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c82a10b4f0c9323d726804c89dd9548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1da65df9df70430d0a095297a628f04c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
⑤若向量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b172cf8d898883d82e973f28c3c3a3e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2cc1f1ef9ad32eef62aefa4c3fc3d6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7dced91de1b8c38aa95ffee0e5dc202.png)
其中,真命题的个数是( )
A.2 | B.3 | C.0 | D.1 |
您最近一年使用:0次
单选题
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较易
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【推荐1】已知向量
,
,且满足
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5f6b6169310ca537f288a2a1cbeb453.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d947be59acd49ffae939a7d1274a1f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65d3dd4a31c6063251f1894a4bebf59c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0812ad6c6b5d23ea4316b5abc2153212.png)
A.13 | B.![]() | C.26 | D.![]() |
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】已知向量
,若
,则
与
夹角的余弦值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acef5848637f11fe4b25e04ee58bf538.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8bf21fef3026cfe445a855c94cab5c84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b45ba716f03748c19b7ce2f99af536ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed492f7b29166ba5c1f0023b05a439c5.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
单选题
|
较易
(0.85)
解题方法
【推荐2】已知
,
,若
,
,则x+y=( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfc4e2320c85265180570f50124eafe4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c16461cd6d88ecaaafbe61ce0c4edcd7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02f7d08d10754ff3903d139768f40530.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65e9ac2a36eb7f9508820277aa753900.png)
A.1 | B.2 | C.-1或1 | D.-2或2 |
您最近一年使用:0次