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如图,一电线杆AB高为10米,当太阳光线与地面的夹角为60°时,其影长AC约为(...
如图,一电线杆AB高为10米,当太阳光线与地面的夹角为60°时,其影长AC约为( )(
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857015_ST/0.png)
取1.732,结果保留3个有效数字)
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857015_ST/images1.png)
A.5.00米
B.8.66米
C.17.3米
D.5.77米
考点分析:
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已知α是锐角,cosα=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857014_ST/0.png)
,则α等于( )
A.30°
B.45°
C.60°
D.90°
查看答案
将(-sin30°)
-2,(-
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857013_ST/0.png)
)
,(-
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857013_ST/1.png)
)
3这三个实数按从小到大的顺序排列,正确的结果是( )
A.(-sin30°)
-2<(-
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857013_ST/2.png)
)
<(-
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857013_ST/3.png)
)
3B.(-sin30°)
-2<(-
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857013_ST/4.png)
)
3<(-
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857013_ST/5.png)
)
C.(-
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857013_ST/6.png)
)
3<(-
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857013_ST/7.png)
)
<(-sin30°)
-2D.(-
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857013_ST/8.png)
)
<(-
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857013_ST/9.png)
)
3<(-sin30°)
-2
查看答案
在△ABC中,∠C=90°,AB=2,AC=1,则sinB的值是( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857012_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857012_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857012_ST/2.png)
D.2
查看答案
tan30°的值等于( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857011_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857011_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857011_ST/2.png)
D.
查看答案
计算:tan60°+2sin45°-2cos30°的结果是( )
A.2
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857010_ST/0.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101402571385700/SYS201311031014025713857010_ST/1.png)
D.1
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