已知数列{a
n满足a
1=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183540428375539/SYS201310241835404283755018_ST/0.png)
,且对任意n∈N*,都有
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183540428375539/SYS201310241835404283755018_ST/1.png)
=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183540428375539/SYS201310241835404283755018_ST/2.png)
.
(Ⅰ)求证:数列{
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183540428375539/SYS201310241835404283755018_ST/3.png)
}为等差数列,并求{a
n}的通项公式;
(Ⅱ)试问数列{a
n}中a
k•a
k+1是否仍是{a
n}中的项?如果是,请指出是数列的第几项;如果不是,请说明理由.
考点分析:
相关试题推荐
如图,已知四棱锥P-ABCD的底面ABCD是边长为1的正方形,PD⊥底面ABCD,且PD=2.
(1)若点E、F分别在棱PB、AD上,且
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183540428375539/SYS201310241835404283755017_ST/0.png)
=4
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183540428375539/SYS201310241835404283755017_ST/1.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183540428375539/SYS201310241835404283755017_ST/2.png)
=4
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183540428375539/SYS201310241835404283755017_ST/3.png)
,求证:EF⊥平面PBC;
(2)若点G在线段PA上,且三棱锥G-PBC的体积为
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183540428375539/SYS201310241835404283755017_ST/4.png)
,试求线段PG的长.
查看答案
已知函数f(x)=x
2-2tx+1,x∈[2,5]有反函数,且函数f(x)的最大值为8,求实数t的值.
查看答案
已知正方形ABCD的面积为36,BC平行于x轴,顶点A、B和C分别在函数y=3log
ax、y=2log
ax和y=log
ax(其中a>1)的图象上,则实数a的值为( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183540428375539/SYS201310241835404283755015_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183540428375539/SYS201310241835404283755015_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183540428375539/SYS201310241835404283755015_ST/2.png)
D.
查看答案
在平面直角坐标系中,横坐标、纵坐标均为整数的点称为整点,如果函数f(x)的图象恰好通过n(n∈N
+)个整点,则称函数f(x)为n阶整点函数.有下列函数:
①f(x)=sin2x;
②g(x)=x
3;
③
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183540428375539/SYS201310241835404283755014_ST/0.png)
;
④φ(x)=lnx.
其中是一阶整点函数的是( )
A.①②③④
B.①③④
C.①④
D.④
查看答案
已知无穷等比数列{a
n}的前n项和为S
n,各项的和为S,且
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131024183540428375539/SYS201310241835404283755013_ST/0.png)
,则其首项a
1的取值范围是( )
A.(-1,0)∪(0,1)
B.(-2,-1)∪(-1,0)
C.(0,1)∪(1,2)
D.(-2,0)∪(0,2)
查看答案