函数f(x)=x2﹣1(x≥0)的反函数为f﹣1(x),则f﹣1(2)的值是( )
A: Hello, Kate!
B: Hi, Bob! ____
A: Is your name on it?
B: No, it isn't. ____
A: That's good. ____
B: OK. ____
A: 270-9158.
B: Thank you.
A: ____
A You're welcome.
B.I lost my dictionary.
C.What's her phone number?
D But a picture of me is in it.
E.You can ask Ms. Miller for help.
已知{fn(x)}满足f1(x)= x1+x2 (x>0),fn+1(x)=f1fn(x),