下列命题:①设a,b是非零实数,若a<b,则ab2>a2b;②若a<b<0,则
;③函数
的最小值是2;④若x,y是正数,且
,则xy的最小值16.其中正确命题的序号是________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec8201ff29a2091d40eee10db6bbc1f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c77f8c77da9a2b724f9e4faa7d0b0af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7f396c5ec8013468c9de9b2cd6f2f4e.png)
更新时间:2021-11-05 13:07:06
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【推荐1】已知a、b、c∈R,给出以下三个命题:①若ab≤0,则a≤0或b≤0;②若a|c|>b|c|,则a
b;③若关于x的实系数方程ax2+bx+c=0有实数根,则b2﹣4ac
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【推荐2】已知
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【推荐2】设
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_______
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【推荐2】在
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