** proof under construction - will post when done and more or less confident it's true.
** also please easy with the downgrades.. i don't understand why i'm getting them.
what is meant by show that?
am i supposed to give an example? sure g(y) can be y/2 if f is x*2. am i supposed to give a proof ? (we are learning the axioms and the lemmas.) in which case sure, again, given the sets A, B, X, Y and g: Y -> X, and f an injective function defined f: A->B with A a subset of X and B a subset of Y. we know that f will map only specific values of X to specific values of Y, i then define f(x) = x*2 and g(y) = y/2 thus g o f = idX is valid.
(i am not sure if this counts as a correct proof, but i am trying)
I can explain it verbally. I understand the concept. but i have NO idea what the question wants from me. "show that" is too vague.