對(duì)實(shí)數(shù)a與b,定義新運(yùn)算“?”:
a?b=.設(shè)函數(shù)f(x)=(x
2-2)?(x-x
2),x∈R.若函數(shù)y=f(x)-c的圖象與x軸恰有兩個(gè)公共點(diǎn),則實(shí)數(shù)c的取值范圍是( ?。?br/>A.
(?∞,?2]∪(?1,)B.
(?∞,?2]∪(?1,?)C.
(?∞,)∪(,+∞)D.
(?1,?)∪[,+∞)
![](http://hiphotos.baidu.com/zhidao/pic/item/5bafa40f4bfbfbed8d4bc9c97bf0f736afc31f71.jpg)
∵
a?b=,
∴函數(shù)f(x)=(x
2-2)?(x-x
2)=
,
由圖可知,當(dāng)c∈
(?∞,?2]∪(?1,?)函數(shù)f(x) 與y=c的圖象有兩個(gè)公共點(diǎn),
∴c的取值范圍是
(?∞,?2]∪(?1,?),
故選B.