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△ABC的三内角A,B,C所对边的长分别为a,b,c设向量,,若,则角C的大小为...
△ABC的三内角A,B,C所对边的长分别为a,b,c设向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240003_ST/0.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240003_ST/1.png)
,若
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240003_ST/2.png)
,则角C的大小为( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240003_ST/3.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240003_ST/4.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240003_ST/5.png)
D.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240003_ST/6.png)
考点分析:
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如图,OM∥AB,点P由射线OM、线段OB及AB的延长线围成的阴影区域内(不含边界).且
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240002_ST/0.png)
,则实数对(x,y)可以是( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240002_ST/1.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240002_ST/2.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240002_ST/3.png)
D.
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已知
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240001_ST/0.png)
,且关于x的方程
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240001_ST/1.png)
有实根,则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240001_ST/2.png)
与
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的夹角的取值范围是( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240001_ST/4.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240001_ST/5.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240001_ST/6.png)
D.
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|
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240000_ST/0.png)
|=1,|
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240000_ST/1.png)
|=
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,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240000_ST/3.png)
•
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240000_ST/4.png)
=0,点C在∠AOB内,且∠AOC=30°,设
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240000_ST/5.png)
=m
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240000_ST/6.png)
+n
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240000_ST/7.png)
(m、n∈R),则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240000_ST/8.png)
等于( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240000_ST/9.png)
B.3
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914524052/SYS201311012304379145240000_ST/10.png)
D.
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已知函数
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914388001/SYS201311012304379143880021_ST/0.png)
.
(1)求证:不论a为何实数f(x)总是为增函数;
(2)确定a的值,使f(x)为奇函数;
(3)当f(x)为奇函数时,求f(x)的值域.
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光线通过一块玻璃,其强度要损失10%,把几块这样的玻璃重叠起来,设光线原来的强度为a,通过x块玻璃后强度为y.
(1)写出y关于x的函数关系式;
(2)通过多少块玻璃后,光线强度减弱到原来的
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230437914388001/SYS201311012304379143880020_ST/0.png)
以下?( lg3≈0.4771)
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