满分5 >
高中数学试题 >
已知向量=(2,3),=(-1,2),若m+n与-2共线,则等于( ) A.- ...
已知向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115215760/SYS201311012246341152157001_ST/0.png)
=(2,3),
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115215760/SYS201311012246341152157001_ST/1.png)
=(-1,2),若m
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115215760/SYS201311012246341152157001_ST/2.png)
+n
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115215760/SYS201311012246341152157001_ST/3.png)
与
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115215760/SYS201311012246341152157001_ST/4.png)
-2
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115215760/SYS201311012246341152157001_ST/5.png)
共线,则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115215760/SYS201311012246341152157001_ST/6.png)
等于( )
A.-
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115215760/SYS201311012246341152157001_ST/7.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115215760/SYS201311012246341152157001_ST/8.png)
C.-2
D.2
考点分析:
相关试题推荐
若A={2,3,4},B={x|x=n•m,m,n∈A,m≠n},则集合B的元素个数为( )
A.5
B.4
C.3
D.2
查看答案
已知数列{a
n}满足a
1=1,na
n+1=(n+1)a
n+cn(n+1)(c为常数)
(1)证明:
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115045068/SYS201311012246341150450022_ST/0.png)
是等差数列;
(2)问是否存在正整数p、q(p±q)使a
p=a
q成立?若存在,请写出C满足的条件,若不存在,说明理由.
(3)设
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115045068/SYS201311012246341150450022_ST/1.png)
,若当n≥4,数列{b
n}为递数列,试求c的最小值.
查看答案
已知二次函数
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115045068/SYS201311012246341150450021_ST/0.png)
(1)f(x)为偶函数,试判断g(x)的奇偶性;
(2)若方程g(x)=x有两个不相等的实根,当a>0时判断f(x)在(-1,1)上的单调性;
(3)若方程g(x)=x的两实根为x
1,x
2f(x)=0的两根为x
3,x
4,求使x
3<x
1<x
2<x
4成立的a的取值范围.
查看答案
一乐器发出的悦耳声音来源于拉紧的弦或木制簧片的振动,它的振动函数为f(x)=2sin(ωx+φ)(ω>0,0<φ≤2π)
(1)若将函数y=2sin2x的图象上的点向右平移
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115045068/SYS201311012246341150450020_ST/0.png)
单位可得到y=f(x)的图象,求φ的值;
(2)若ω在集合{2,3,4}中任取一个数,φ在
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115045068/SYS201311012246341150450020_ST/1.png)
中任取一个数,从这些函数中任意抽取两个,试求其图象能经过相同的平移后得到y=2sinωx图象的概率.
查看答案
在△ABC中,a,b,c分别为内角A,B,C所对的边,且满足
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115045068/SYS201311012246341150450019_ST/0.png)
.
(1)求A的大小;
(2)现给出三个条件:①a=2;②B=45°;③c=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101224634115045068/SYS201311012246341150450019_ST/1.png)
b
试从中选出两个可以确定△ABC的条件,写出你的选择,并以此为依据求△ABC的面积(只需写出一个选定方案即可)
查看答案