Math Help - I Need a Binary Operation

Define a binary operation on the rationals so that the map defined by is an isomorphism between sets with binary operations. Prove that is an isomorphism.

By Isomorphism i mean i need to find a binary operation such that for all u, v in ,

Originally Posted by kbartlett

Define a binary operation on the rationals so that the map defined by is an isomorphism between sets with binary operations. Prove that is an isomorphism.

By Isomorphism i mean i need to find a binary operation such that for all u, v in ,

You want to hold for all .
Therefore, .
Thus,

thankyou, it seems so obvious now. The big words just confussed me .

Do u know how i could go about Proving that is an isomorphism.