已知实数x,y满足
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100050853633632/SYS201311031000508536336012_ST/0.png)
,则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100050853633632/SYS201311031000508536336012_ST/1.png)
的最小值是
.
考点分析:
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一个底面为正三角形且侧棱垂直于底面的三棱柱内接于半径为
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100050853633632/SYS201311031000508536336011_ST/0.png)
的球,则该棱柱体积的最大值为( )
A.
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B.
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C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100050853633632/SYS201311031000508536336011_ST/3.png)
D.
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已知
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100050853633632/SYS201311031000508536336010_ST/0.png)
,M、N是椭圆上关于原点对称的两点,P是椭圆上任意一点,且直线PM、PN的斜率分别为k
1、k
2(k
1k
2≠0),若|k
1|+|k
2|的最小值为1,则椭圆的离心率为( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100050853633632/SYS201311031000508536336010_ST/1.png)
B.
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C.
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D.
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已知函数
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100050853633632/SYS201311031000508536336009_ST/0.png)
(ω>0)和g(x)=3cos(2x+φ)的图象的对称中心完全相同,若
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100050853633632/SYS201311031000508536336009_ST/1.png)
,则f(x)的取值范围是( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100050853633632/SYS201311031000508536336009_ST/2.png)
B.[-3,3]
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100050853633632/SYS201311031000508536336009_ST/3.png)
D.
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若直线2ax-by+2=0(a>0,b>0)被圆x
2+y
2+2x-4y+1=0所截得的弦长为4,则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100050853633632/SYS201311031000508536336008_ST/0.png)
的最小值为( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100050853633632/SYS201311031000508536336008_ST/1.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100050853633632/SYS201311031000508536336008_ST/2.png)
C.2
D.4
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设非零向量
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、
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、
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满足
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100050853633632/SYS201311031000508536336007_ST/3.png)
,则
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=( )
A.150°
B.120°
C.60°
D.30°
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