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在Rt△ABC中,∠C=90°,下列式子中不一定成立的是( ) A.tanA= ...
在Rt△ABC中,∠C=90°,下列式子中不一定成立的是( )
A.tanA=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103000125468232790/SYS201311030001254682327006_ST/0.png)
B.sin
2A+sin
2B=1
C.sin
2A+cos
2A=1
D.sinA=sinB
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在Rt△ABC中,∠C=90°,下列各式中正确的是( )
A.sinA=sinB
B.tanA=tanB
C.sinA=cosB
D.cosA=cosB
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已知在Rt△ABC中,∠C=90°.若sinA=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103000125468232790/SYS201311030001254682327001_ST/0.png)
,则sinB等于( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103000125468232790/SYS201311030001254682327001_ST/1.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103000125468232790/SYS201311030001254682327001_ST/2.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103000125468232790/SYS201311030001254682327001_ST/3.png)
D.1
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