I am a bit stuck on this problem. Here is how I've approached it:Let . Prove that if m is rational, then x and y must also be rational.
Let . Then
Then from here I don't know what to do. We can't express x or y solely in terms of c and d. And expressing x in terms of c, d and y (or y in terms of c, d and x) is inconclusive because we cannot assume that y and x respectively are rational, as that is what we are trying to show.
Any help, please? Many thanks!