Is the ring $\Bbb Z[x] /\langle x^2-1\rangle$ isomorphic to $\Bbb Z \times \Bbb Z$???
26749
$\mathbb{Z}[X]/(X^2-1)$ is not isomorphic with $\mathbb{Z}\times \mathbb{Z}$
33781
Is $\mathbb{Z}[x]/(x^2+1)$ isomorphic to $\mathbb{Z}[i]$?
133636
Is $\mathbb Z[X]/(X^2-1)$ a domain?
114916
$\mathbb Z_{mn}$ isomorphic to $\mathbb Z_m\times\mathbb Z_n$ whenever $m$ and $n$ are coprime
157915
Isomorphism between the group $(\mathbb Z[x], +)$ and $(\mathbb Q_{>0}, .)$
133612
How many isomorphisms are there from $\Bbb Z_{12}$ to $\Bbb Z_{4} \oplus \Bbb Z_{3}$?
87160
Prove $\mathbb{Z}_3[x]/(x^2+1)$ and $\mathbb{Z}_3[x]/(x^2+x-1)$ are isomorphic.
106911
Square root of $-1$ in the ring $\mathbb{R}[x]/\langle(x^2+1)^2\rangle$
55900
Is there a ring homomorphism $M_2(\mathbb Z)\to \mathbb Z$?
141124
Automorphisms of the ring $\Bbb Z[x]$ of polynomials with integer coefficients
91627
What is a primary decomposition of the ideal $I = \langle xy, x - yz \rangle$?
61292
How to know which elements are in the Quotient Ring $\mathbb{Z}[x]/\langle x, 2\rangle$?
149973
Showing the following coordinate rings are not isomorphic
158232
Tensor product of a module with an ideal is isomorphic to their standard product
55393
Existence of a group isomorphism between $(\mathbb K,+)$ and $(\mathbb K^\times,\cdot)$
97999
Explain these ring isomorphisms
148550
Units in quotient ring of $\mathbb Z[X]$