zxz轴承

Searching…

math.stackexchange.com

Describe all group homomorphisms from Z×Z into Z

May 25, 2018 · I find a similar post, which is Describe all ring homomorphisms from Z×Z into Z. I also know the difference between group and ring. But in this case, from ZxZ into Z, I'm so confused. The textbook ...

math.stackexchange.com

Show that $Z\times Z$ is not cyclic... [duplicate]

Recall that an infinite cyclic group is isomorphic to $\mathbb {Z}$. We wish to show that we do not have an isomorphism between $\mathbb {ZxZ\;and\;Z}$. Note that $\mathbb {ZxZ}$ is an infinite group (under addition o...