Proof f(x)=x for x Rational w/ f(x+y)=f(x)+f(y), f(xy)=f(x)f(y)

[jgens]

You're not understanding what you're proving then. If you prove part (c) and (d) correctly, there's no need to assume that any of the numbers must be rational. You may want to go back and re-examine or re-do the proofs of these facts if you haven't understood them already.

 

[SpringPhysics]

I think I've got it now. Thanks for putting up with my incompetency.