满分5 >
高中数学试题 >
已知二次函数f(x)=ax2+bx+c的导数为f′(x),f′(0)>0,对于任...
已知二次函数f(x)=ax
2+bx+c的导数为f′(x),f′(0)>0,对于任意实数x都有f(x)≥0,则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101221254901669066/SYS201311012212549016690011_ST/0.png)
的最小值为( )
A.3
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101221254901669066/SYS201311012212549016690011_ST/1.png)
C.2
D.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101221254901669066/SYS201311012212549016690011_ST/2.png)
考点分析:
相关试题推荐
设a,b,c∈(-∞,0),则a+
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101221254901669066/SYS201311012212549016690010_ST/0.png)
,b+
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101221254901669066/SYS201311012212549016690010_ST/1.png)
,c+
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101221254901669066/SYS201311012212549016690010_ST/2.png)
( )
A.都不大于-2
B.都不小于-2
C.至少有一个不大于-2
D.至少有一个不小于-2
查看答案
以正弦曲线y=sinx上一点P为切点的切线为直线l,则直线l的倾斜角的范围是( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101221254901669066/SYS201311012212549016690009_ST/0.png)
∪
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101221254901669066/SYS201311012212549016690009_ST/1.png)
B.[0,π)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101221254901669066/SYS201311012212549016690009_ST/2.png)
D.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101221254901669066/SYS201311012212549016690009_ST/3.png)
∪
查看答案
当x≠0时,有不等式( )
A.e
x<1+
B.e
x>1+
C.当x>0时e
x<1+x,当x<0时e
x>1+
D.当x<0时e
x<1+x,当x>0时e
x>1+
查看答案
设a,b,c三数成等比数列,而x,y分别为a,b和b,c的等差中项,则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101221254901669066/SYS201311012212549016690007_ST/0.png)
=( )
A.1
B.2
C.3
D.不确定
查看答案
对两个变量y与x进行线性回归分析,分别选择了4个不同的模型,它们的相关系数r如下,其中拟合程度最好的模型是( )
A.模型1的相关系数r为0.98
B.模型2的相关系数r为0.80
C.模型3的相关系数r为0.50
D.模型4的相关系数r为0.25
查看答案