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已知向量,满足(+2)•(-)=-6,且||=1,||=2,则与的夹角为 .
已知向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102448159052617/SYS201311031024481590526012_ST/0.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102448159052617/SYS201311031024481590526012_ST/1.png)
满足(
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102448159052617/SYS201311031024481590526012_ST/2.png)
+2
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102448159052617/SYS201311031024481590526012_ST/3.png)
)•(
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102448159052617/SYS201311031024481590526012_ST/4.png)
-
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102448159052617/SYS201311031024481590526012_ST/5.png)
)=-6,且|
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102448159052617/SYS201311031024481590526012_ST/6.png)
|=1,|
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102448159052617/SYS201311031024481590526012_ST/7.png)
|=2,则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102448159052617/SYS201311031024481590526012_ST/8.png)
与
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102448159052617/SYS201311031024481590526012_ST/9.png)
的夹角为
.
考点分析:
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