满分5 >
高中数学试题 >
已知非零向量,,满足++=0,向量与夹角为120°,且||=2||,则向量与的夹...
已知非零向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519005_ST/0.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519005_ST/1.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519005_ST/2.png)
满足
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519005_ST/3.png)
+
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519005_ST/4.png)
+
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519005_ST/5.png)
=0,向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519005_ST/6.png)
与
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519005_ST/7.png)
夹角为120°,且|
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519005_ST/8.png)
|=2|
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519005_ST/9.png)
|,则向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519005_ST/10.png)
与
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519005_ST/11.png)
的夹角为( )
A.60°
B.90°
C.120°
D.150°
考点分析:
相关试题推荐
已知平面α∩β=l,m是α内不同于l的直线,那么下列命题中错误 的是( )
A.若m∥β,则m∥l
B.若m∥l,则m∥β
C.若m⊥β,则m⊥l
D.若m⊥l,则m⊥β
查看答案
执行如图所示的程序框图,若输出x的值为23,则输入的x值为( )
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519003_ST/images0.png)
A.0
B.1
C.2
D.11
查看答案
在极坐标系下,已知圆C的方程为ρ=2cosθ,则下列各点在圆C上的是( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519002_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519002_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131025123656965151908/SYS201310251236569651519002_ST/2.png)
D.
查看答案
已知数列{a
n}为等差数列,S
n是它的前n项和.若a
1=2,S
3=12,则S
4=( )
A.10
B.16
C.20
D.24
查看答案
已知集合A={x∈R|0<x<3},B={x∈R|x
2≥4},则A∩B=( )
A.{x|2<x<3}
B.{x|2≤x<3}
C.{x|x≤-2或2≤x<3}
D.R
查看答案