Doubt in Definition of Inverse of $y=x^n$

Question

Attaching Snapshot

[From Calculus: Concepts and Methods By Ken Binmore and Joan Davies, suggested by myi University]

I can't figure out whether it is a typo or I don't understand something. The very last sentence, why it says "inverse function at any $x > 0$", shouldn't it be "at any $x \ge 0$", because the domain includes $0$?

Answer 1

You are correct. Although what they say is not wrong, they could say more than what they do.