Does $-1$ have a square root in the ring $\frac{\mathbb R[x]}{\langle(x^2+1)^2\rangle}$?
106911
Square root of $-1$ in the ring $\mathbb{R}[x]/\langle(x^2+1)^2\rangle$
102316
why $(r+I)(s+I) = rs + I$ in the quotient ring $R ?$
31933
$x^2 = 1$ in the ring $\mathbb{Z}/n \mathbb{Z}$
129521
Is $\sqrt[3]{5}$ in $\mathbb Q(\sqrt[3]{2})$?
115296
Under what conditions does a matrix $A$ have a square root?
7500
$\arctan$ of a square root as a rational multiple of $\pi$
77076
Proof that $(x-1)^2$ divides a $nx^{n+1} – (n+1)x^{n}+1$
60261
Is $\sqrt{x^2}=|x|$ or $=x$? Isn't $(x^2)^\frac12=x?$
32443
Find the kernel of a ring homomorphism $f(x)\to f(\sqrt 2)$
154945
$|px^2+qx+r|\le1$ for all $x$ in $[-1; 1]$, show that $|rx^2+qx+p|\le2$ for all $x$ in $[-1; 1]$
68838
Why $\sqrt[3]{3}\not\in \mathbb{Q}(\sqrt[3]{2})$?
11938
What happens if we remove the requirement that $\langle R, + \rangle$ is abelian from the definition of a ring?
43453
Is ${\sqrt2^{\sqrt2^{\sqrt2^{\sqrt2^\sqrt2}}}}^{...}=4$ correct?
26644
Does this give a localization of a ring?
84189
Is $\mathbb{C}$ equal to $\mathbb{R}^2$?
73689
A question about the equivalence relation on the localization of a ring.
57166
Showing that $\Bbb R[x] / \langle x^2 + 1 \rangle$ is isomorphic to $\Bbb C$ question