满分5 >
初中数学试题 >
(1999•辽宁)在Rt△ABC中,∠C=90°,a,b,c分别是∠A,∠B,∠...
(1999•辽宁)在Rt△ABC中,∠C=90°,a,b,c分别是∠A,∠B,∠C的对边,下列关系式中错误的是( )
A.b=c•cosB
B.b=a•tanB
C.a=c•sinA
D.a=b•cotB
考点分析:
相关试题推荐
(1999•内江)1.224、
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232807247312829/SYS201310212328072473128004_ST/0.png)
、π、
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232807247312829/SYS201310212328072473128004_ST/1.png)
、sinθ、cosθ这六个数中,无理数有( )
A.1个
B.2个
C.3个
D.4个
查看答案
(1999•南京)△ABC中,∠C=90°,∠A,∠B,∠C所对的边分别是a,b,c,则sinA等于( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232807247312829/SYS201310212328072473128003_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232807247312829/SYS201310212328072473128003_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232807247312829/SYS201310212328072473128003_ST/2.png)
D.
查看答案
(1999•成都)在Rt△ABC中,CD为斜边AB上的高,已知AD=8,BD=4,那么tanA的值是( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232807247312829/SYS201310212328072473128002_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232807247312829/SYS201310212328072473128002_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232807247312829/SYS201310212328072473128002_ST/2.png)
D.
查看答案
(1999•温州)如图,△ABC的外接圆⊙O的直径BE交AC于点D,已知弧BC等于120°,
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232807247312829/SYS201310212328072473128001_ST/0.png)
,则关于x的一元二次方程
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232807247312829/SYS201310212328072473128001_ST/1.png)
根的情况是( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232807247312829/SYS201310212328072473128001_ST/images2.png)
A.没有实数恨
B.有两个相等的正实数根
C.有两个相等的实数根
D.有两个不相等的正实数根
查看答案
(1999•福州)在⊙O中,半径R=1,弦AB=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232807247312829/SYS201310212328072473128000_ST/0.png)
,弦AC=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232807247312829/SYS201310212328072473128000_ST/1.png)
,则∠BAC的度数为( )
A.75°
B.15°
C.75°或15°
D.90°或60°
查看答案