在△ABC中,角A、B、C的对应边分别为a、b、c,若lga-lgb=lgcosB-lgcosA.
(1)判断△ABC的形状;
(2)若a、b满足:函数y=ax+3的图象与函数y=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183128917458383/SYS201310241831289174583016_ST/0.png)
x-b的图象关于直线y=x对称,求边长c.
考点分析:
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已知函数f(x)=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183128917458383/SYS201310241831289174583015_ST/0.png)
(a>0,a≠1),在同一坐标系中,y=f
-1(x)与y=a
|x-1|的图象可能是( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183128917458383/SYS201310241831289174583015_ST/images1.png)
B.
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C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183128917458383/SYS201310241831289174583015_ST/images3.png)
D.
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设x>0,y>0,且xy-(x+y)=1,则( )
A.x+y≤2
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B.x+y≥2
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183128917458383/SYS201310241831289174583014_ST/1.png)
+2
C.x+y≤(
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+1)
2D.x+y≥(
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+1)
2
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设函数f(x)=Asin(ωx+φ)(A≠0,ω>0,)
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的图象关于直线
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对称,它的周期是π,则( )
A.f(x)的图象过点
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上是减函数
C.f(x)的一个对称中心是
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183128917458383/SYS201310241831289174583013_ST/4.png)
D.f(x)的最大值是A
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已知向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183128917458383/SYS201310241831289174583012_ST/0.png)
={cosα,sinα},
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183128917458383/SYS201310241831289174583012_ST/1.png)
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A.
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B.
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C.
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D.
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与
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183128917458383/SYS201310241831289174583012_ST/6.png)
的夹角为α+β
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