已知
,
,向量
与
的夹角为
.
(1)求:
;
(2)若
,求实数
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf61a8ac4f02512488f99111f173160c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f744c4442e4294dc9e8a7a35cf0243ee.png)
![](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/4a12c461765806bbfb872e7e8aa410c8.png)
(1)求:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/962a3ab9c7c90eceeaba7a9d7de8021f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/591c3e5f96669e8718669f513c663b89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
更新时间:2017-04-02 10:49:12
|
【知识点】 平面向量的数量积
相似题推荐
解答题-问答题
|
较易
(0.85)
【推荐1】若向量
=(1,1),
=(2,5),
=(3,x).
(1)若
,求x的值;
(2)若
,求x的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/969604545902c9a66549a4a44ec3a3c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90ab17fd4247cdd710c363d5d3fbc5bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8c308ea87b699ee1dcb879a568899de.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5de7352b1f20f15d9cac0c85f2042e1f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8edd6031700960d129ae1642d29aa018.png)
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
解题方法
【推荐2】已知向量
与向量
的夹角为
,其中
、
、
是
的内角.
(1)求
的大小;
(2)求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77b9c3c1136d4c0aca336886a1ac520c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72ec8310868cb3d0a6abcd53923a2016.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac1a63ab608517bb10aa036783dfb51f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0577566dbcc526fb6f783491a4784902.png)
您最近一年使用:0次