Existence of multiplicative inverse in field $\mathbb{Q}(\sqrt{d})$
112556
When is $F(\sqrt c)$ a field?
39642
Efficient way to find $[\mathbb{Q}(\sqrt{5}, \sqrt{3}, \sqrt{2}): \mathbb{Q}(\sqrt{3}, \sqrt{2})]$
63390
Infinite algebraic extensions of $\mathbb{Q}$
106914
Existence of Irreducible polynomials over $\mathbb{Z}$ of any given degree
8087
Algebraic integers of $\mathbb{Q}(\sqrt{m})$ for $m$ a squarefree integer
20613
Units (invertibles) of polynomial rings over a field
95459
$\mathbb{Q}(\sqrt{2+\sqrt{2}})$ is Galois over $\mathbb{Q}$?
53701
Unique quadratic subfield of $\mathbb{Q}(\zeta_p)$ is $\mathbb{Q}(\sqrt{p})$ if $p \equiv 1$ $(4)$, and $\mathbb{Q}(\sqrt{-p})$ if $p \equiv 3$ $(4)$
72144
Show that $\mathbb Q(\sqrt p) \not\simeq\mathbb Q(\sqrt q)$
79226
Discrete non archimedean valued field with infinite residue field
146591
Inseparable polynomial over a non-perfect field
57846
Multiplicative inverse in $\operatorname{GF}(2^8)$?
63280
Show that the set $\mathbb{Q}[\sqrt{2}] = \{a + b \sqrt{2} \mid a, b \in \mathbb{Q}\}$ is a field with the usual multiplication and addition.
145140
Subfield of $\mathbb{Q}(\sqrt[n]{a})$
120401
Does there exist a pair of infinite fields, the additive group of one isomorphic to the multiplicative group of the other?
157496
Determine the Galois group of $\mathbb{Q}(\sqrt{a+b\sqrt{d}})$
69721
$(a,b) \mathbin\# (c,d)=(a+c,b+d)$ and $(a,b) \mathbin\&(c,d)=(ac-bd(r^2+s^2), ad+bc+2rbd)$. Multiplicative inverse?