满分5 >
高中数学试题 >
已知函数y=f(x)关于原点对称,且当x∈(0,+∞)时,f(x)+xf'(x)...
已知函数y=f(x)关于原点对称,且当x∈(0,+∞)时,f(x)+xf'(x)>0成立,若a=20.2•f(20.2),b=log0.3π•f(log0.3π),c=log39•f(log39),则a,b,c的大小关系是( )
A.c>a>b
B.a>b>c
C.c>b>a
D.a>c>b
考点分析:
相关试题推荐
某宾馆有50个房间供游客居住,当每个房间定价为每天180元时,房间会全部住满;房间定价每增加10元时,就会有一个房间空闲.如果游客居住房间,宾馆每间每天需花费20元的各种维护费用,要想宾馆利润最大,每间房的定价为每天( )
A.170元
B.300元
C.350 元
D.400元
查看答案
设f(x)=ax
3-3ax
2+b在区间[-1,2]上的最大值为3,最小值为-21,且a>0,则( )
A.a=6,b=3
B.a=3,b=6
C.a=3,b=3
D.a=2,b=-3
查看答案
如图,在空间直角坐标系中有直三棱柱ABC-A
1B
1C
1,CA=CC
1=2CB,则直线BC
1与直线AB
1夹角的余弦值为( )
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743033262/SYS201311030959097430332008_ST/images0.png)
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743033262/SYS201311030959097430332008_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743033262/SYS201311030959097430332008_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743033262/SYS201311030959097430332008_ST/2.png)
D.
查看答案
圆ρ=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743033262/SYS201311030959097430332007_ST/0.png)
(cosθ+sinθ)的圆心的极坐标是( )
A.(1,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743033262/SYS201311030959097430332007_ST/1.png)
)
B.(
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743033262/SYS201311030959097430332007_ST/2.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743033262/SYS201311030959097430332007_ST/3.png)
)
C.(
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743033262/SYS201311030959097430332007_ST/4.png)
,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743033262/SYS201311030959097430332007_ST/5.png)
)
D.(2,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103095909743033262/SYS201311030959097430332007_ST/6.png)
)
查看答案
设函数f(x)=1-e
x的图象与x轴相交于点P,则曲线在点P的切线方程为( )
A.y=-x+1
B.y=x+1
C.y=-
D.y=
查看答案