已知数列{a
n}中,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232015_ST/0.png)
,则a
n=
.
考点分析:
相关试题推荐
实数x,y满足不等式组
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232014_ST/0.png)
则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232014_ST/1.png)
的范围
.
查看答案
关于平面向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/0.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/1.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/2.png)
,有下列三个命题:
①若
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/3.png)
•
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/4.png)
=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/5.png)
•
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/6.png)
,则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/7.png)
=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/8.png)
、
②若
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/9.png)
=(1,k),
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/10.png)
=(-2,6),
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/11.png)
∥
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/12.png)
,则k=-3.
③非零向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/13.png)
和
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/14.png)
满足|
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/15.png)
|=|
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/16.png)
|=|
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/17.png)
-
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/18.png)
|,则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/19.png)
与
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/20.png)
+
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232013_ST/21.png)
的夹角为60°.
其中真命题的序号为
.(写出所有真命题的序号)
查看答案
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232012_ST/images0.png)
如图,测量河对岸的塔高AB时,可以选与塔底B在同一水平面内的两个测点C与D.测得∠BCD=15°,∠BDC=30°,CD=30米,并在点C测得塔顶A的仰角为60°,则塔高AB=
米.
查看答案
定义在R上的偶函数f(x)满足f(x+1)=-f(x),且在[-1,0]上单调递增,a=f(3),b=f(
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232011_ST/0.png)
),c=f(2),则a,b,c大小关系是( )
A.a>b>c
B.a>c>b
C.b>c>a
D.c>b>a
查看答案
已知某个几何体的三视图如下,根据图中标出的尺寸(单位:cm),可得这个几何体的体积是( )
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232010_ST/images0.png)
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232010_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231405921723291/SYS201311012314059217232010_ST/1.png)
C.2000cm
3D.4000cm
3
查看答案