Thanks for replying.
Right, I'm pretty sure that the function being from R to R is the part that I got wrong. He told me that later in the day(or, at least, that's what I managed to make of the three or so words he said); earlier he had told me to find the possible values of x, which is what...
Homework Statement
A friend of mine tried to classify for the IMO a few days ago (he didn't do so well). A problem he had to solve was:
f(x + xy + f(y)) = (f(x) + 1/2)(f(x) + 1/2)
I didn't really understand what he said later. First he told me to find the values of X and Y for which...