满分5 >
高中数学试题 >
如图,在△ABC中,D是边AC上的点,且AB=AD,2AB=BD,BC=2BD,...
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230745570248732/SYS201311012307455702487008_ST/images0.png)
如图,在△ABC中,D是边AC上的点,且AB=AD,2AB=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230745570248732/SYS201311012307455702487008_ST/0.png)
BD,BC=2BD,则sinC的值为( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230745570248732/SYS201311012307455702487008_ST/1.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230745570248732/SYS201311012307455702487008_ST/2.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230745570248732/SYS201311012307455702487008_ST/3.png)
D.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230745570248732/SYS201311012307455702487008_ST/4.png)
考点分析:
相关试题推荐
设平面内有n条直线(n≥3),其中有且仅有两条直线互相平行,任意三条直线不过同一点.若用f(n)表示这n条直线交点的个数,则f(4)=( ) 当n>4时,f(n)=( )
A.4,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230745570248732/SYS201311012307455702487007_ST/0.png)
B.4,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230745570248732/SYS201311012307455702487007_ST/1.png)
C.5,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230745570248732/SYS201311012307455702487007_ST/2.png)
D.5,
查看答案
下面结论正确的是( )
A.若a>b,则有
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230745570248732/SYS201311012307455702487006_ST/0.png)
B.若a>b,则有a|c|>b|c|
C.若a>b,则有|a|>b
D.若a>b,则有
查看答案
在△ABC中,角A、B、C所对的边分别是a、b、c,并且a=1,b=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230745570248732/SYS201311012307455702487005_ST/0.png)
,A=30°,则c的值为( )
A.2
B.1
C.1或2
D.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101230745570248732/SYS201311012307455702487005_ST/1.png)
或2
查看答案
已知等差数列{a
n}和等比数列{b
n},它们的首项是一个相等的正数,且第3项也是相等的正数,则a
2与b
2的大小关系为( )
A.a
2≤b
2B.a
2≥b
2C.a
2<b
2D.a
2>b
2
查看答案
设等差数列a
n的前n项之和为S
n,已知S
10=100,则a
4+a
7=( )
A.12
B.20
C.40
D.100
查看答案