Teacher:____?(这是什么?)
Student: It's____(一个苹果)
Teacher: What colour is it?
Student:It's ____.(红色)
若函数f(x)=x2+ax-2,x≤1-ax,x>1(a>0,且a≠1)在(0,+∞)上是增函数,则a的范围是( )