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如图,在Rt△ABC中,∠C=90°,AC=3.将其绕B点顺时针旋转一周,则分别...
如图,在Rt△ABC中,∠C=90°,AC=3.将其绕B点顺时针旋转一周,则分别以BA、BC为半径的圆形成一圆环.该圆环的面积为( )
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A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101630908708785/SYS201311031016309087087003_ST/0.png)
π
B.3π
C.9π
D.6π
考点分析:
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A.30°
B.60°
C.90°
D.120°
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如图,⊙O上有两点A与P,若P点在圆上匀速运动一周,那么弦AP的长度d与时间t的关系可能是下列图形中的( )
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A.①
B.③
C.②或④
D.①或③
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在平面直角坐标系内存在⊙A,A(b,0),⊙A交x轴于O(0,0)、B(2b,0),在y轴上存在一动点C(C不与原点O重合),直线l始终过A、C,直线l交⊙A于E、F,在半圆EF上存在一点动点D且D不与E、F重合,则S
△DEA的最大值为( )
A.
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B.
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D.无法判断
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若f(x)>0,符号∫
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,则A,B,C的大小关系为
.
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已知二次函数y=a(a+1)x
2-(2a+1)x+1(a>0)的图象顶点为A,与x轴交点为B,C,则tan∠ABC=
.
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