- #1
semidevil
- 157
- 2
find an isomorphism from from the group of integers under addition to the group of even integers under addition.
I know, very simple question, but I don't know what I am doing here...
the hint in the book says to try n to 2n. I thought of that too, since it specificaly says integers to even integers.
the books says to prove injective, surjective, and phi(x,y) = phi(x) phi(y).
so what do I do? start x = 2y and prove x = y?
I think I'm wronng...
I know, very simple question, but I don't know what I am doing here...
the hint in the book says to try n to 2n. I thought of that too, since it specificaly says integers to even integers.
the books says to prove injective, surjective, and phi(x,y) = phi(x) phi(y).
so what do I do? start x = 2y and prove x = y?
I think I'm wronng...