已知函数f(x)=sinx+cosx,f′(x)是f(x)的导函数.
(1)求函数F(x)=f(x)f′(x)+[f(x)]
2的最大值和最小正周期;
(2)若f(x)=2f'(x),求
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的值.
考点分析:
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计算
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231646787672734/SYS201311012316467876727015_ST/0.png)
,可以采用以下方法:构造恒等式
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231646787672734/SYS201311012316467876727015_ST/1.png)
,两边对x求导,得
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231646787672734/SYS201311012316467876727015_ST/2.png)
,在上式中令x=1,得
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231646787672734/SYS201311012316467876727015_ST/3.png)
.类比上述计算方法,计算
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=
.
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给出下列四个结论:
①抛物线y=-2x
2的焦点坐标是
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;
②已知直线l
1:ax+3y-1=0,l
2:x+by+1=0则l
1⊥l
2充要条件是
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231646787672734/SYS201311012316467876727014_ST/1.png)
;
③
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231646787672734/SYS201311012316467876727014_ST/2.png)
的展开式中x
4项的系数为210,则实数m的值为1;
④回归直线
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231646787672734/SYS201311012316467876727014_ST/3.png)
必过点
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231646787672734/SYS201311012316467876727014_ST/4.png)
.
其中结论正确的是
.(将所有正确结论的序号都写上)
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一个单位共有职工200人,其中不超过45岁的有120人,超过45岁的有80人.为了调查职工的健康状况,用分层抽样的方法从全体职工中抽取一个容量为25的样本,应抽取超过45岁的职工
人.
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已知递增的等比数列{a
n}满足a
2+a
3+a
4=28,且a
3+2是a
2、a
4的等差中项.求数列{a
n}的通项公式.
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已知双曲线
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231646787672734/SYS201311012316467876727011_ST/0.png)
的左右焦点分别为F
1,F
2,P为双曲线右支一的任意一点,若
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231646787672734/SYS201311012316467876727011_ST/1.png)
的最小值为8a,则双曲线离心率的取值范围是( )
A.(0,+∞)
B.(1,2]
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231646787672734/SYS201311012316467876727011_ST/2.png)
D.(1,3]
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