How do I prove that this is or isn't isomorphic?
114916
$\mathbb Z_{mn}$ isomorphic to $\mathbb Z_m\times\mathbb Z_n$ whenever $m$ and $n$ are coprime
37904
Prove that the multiplicative groups $\mathbb{R} - \{0\}$ and $\mathbb{C} - \{0\}$ are not isomorphic.
9140
Show $\operatorname{Aut}(C_2 \times C_2)$ is isomorphic to $S_3=D_6$
116594
Finite fields are isomorphic
139162
Complex number isomorphic to certain $2\times 2$ matrices?
58707
Prove Quotient Group Isomorphism
26749
$\mathbb{Z}[X]/(X^2-1)$ is not isomorphic with $\mathbb{Z}\times \mathbb{Z}$
58009
How to show that $\mathbb Q(\sqrt 2)$ is not field isomorphic to $\mathbb Q(\sqrt 3).$
92599
Prove there generally is no isomorphism between $R[x]/(x^2-a)$ and $R^2$
83001
Easier way to show $(\mathbb{Z}/(n))[x]$ and $\mathbb{Z}[x] / (n)$ are isomorphic
115350
An example of a Banach space isomorphic but not isometric to a dual Banach space
86015
$\mathbb Q[x]/(x^2+1)$ is not isomorphic to $\mathbb Q[x]/(x^2+2)$
44923
Show that matrix under addition is isomorphic with the group of complex numbers under addition
18048
Easy criteria to determine isomorphism of fields?
106091
Showing $\mathcal{P}(X)$ is isomorphic to $2^X$
5996
Are $(\mathbb{R},+)$ and $(\mathbb{C},+)$ isomorphic as additive groups?
156679
$K[X,Y]/(XY-1)$ not isomorphic to $K[T]$