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下列函数:①;②;③;④f(x)=x2+2x,定义域相同的是( ) A.①② B...
下列函数:①
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;②
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102024845480082/SYS201311031020248454800003_ST/1.png)
;③
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103102024845480082/SYS201311031020248454800003_ST/2.png)
;④f(x)=x
2+2x,定义域相同的是( )
A.①②
B.②③
C.③①
D.④①
考点分析:
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