Hi, This is one of my hw problem, N I just got no clue wat it is askin:
Suppose G: R to R is a field isomorphism, i.e. is a 1-1 and onto function such that G(x+y)=G(x)+G(y) and G(xy)=G(x)G(y) for all x and y belongs to R.
Prove that G preserves order. Deduce that G is the identity function.