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阅读理【解析】 对于任意正实数a、b,∵≥0,∴≥0,∴a+b≥,只有当a=b时...
阅读理【解析】
对于任意正实数a、b,∵
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185743849628967/SYS201311011857438496289019_ST/0.png)
≥0,∴
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185743849628967/SYS201311011857438496289019_ST/1.png)
≥0,∴a+b≥
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185743849628967/SYS201311011857438496289019_ST/2.png)
,只有当a=b时,等号成立.
结论:在a+b≥
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185743849628967/SYS201311011857438496289019_ST/3.png)
(a、b均为正实数)中,若ab为定值p,则a+b≥
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185743849628967/SYS201311011857438496289019_ST/4.png)
,只有当a=b时,a+b有最小值
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185743849628967/SYS201311011857438496289019_ST/5.png)
.
根据上述内容,回答:若m>0,只有当m=
时,
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185743849628967/SYS201311011857438496289019_ST/6.png)
有最小值
.
考点分析:
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如果a
2+11a+16=0,b
2+11b+16=0(a≠b),那么
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185743849628967/SYS201311011857438496289018_ST/0.png)
的值等于
.
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阅读理【解析】
符号
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185743849628967/SYS201311011857438496289016_ST/0.png)
称为二阶行列式,规定它的运算法则为:
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185743849628967/SYS201311011857438496289016_ST/1.png)
=ad-bc,例如
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185743849628967/SYS201311011857438496289016_ST/2.png)
=3×6-4×5=18-20=-2,请根据阅读理解化简下面的二阶行列式:
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185743849628967/SYS201311011857438496289016_ST/3.png)
=
.
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已知函数y=x
2+2(a+2)x+a
2的图象与x轴有两个交点,且都在x轴的负半轴上,则a的取值范围是
.
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已知方程组
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185743849628967/SYS201311011857438496289014_ST/0.png)
的解为
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131101185743849628967/SYS201311011857438496289014_ST/1.png)
且|k|<2,则a-b的取值范围是
.
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