Why is it that $\sqrt{4}$ is only $2$, not $\pm 2$?
3955
Square roots -- positive and negative
53331
$\mathbb{Q}(\sqrt2, \sqrt3)$ is not isomorphic to $\mathbb{Q}(\sqrt[4]2)$
42842
Proof for $\epsilon$ closeness to $\sqrt{2}$ for all values of $\epsilon$
68635
When is $2$ a quadratic residue mod $p$?
33184
Something strange about $\sqrt{ 4+ \sqrt{ 4 + \sqrt{ 4-x}}}=x$ and its friends
62485
How can I prove $\sqrt{2}^{\sqrt{2}^{\sqrt{2}^{\sqrt{2}^{\sqrt{2}...}}}}=2$
101349
$-1$ isn't a quadratic residue $\pmod{p}, p=4k+3$.
112319
Sieve of Eratosthenes : why $\sqrt n$ work?
81381
Why does the domain and range of $\sqrt x$ contain only positive real numbers?
22129
Why is $\sqrt{\sum_{i=1}^n |v_i|^2} \leq \sum_{i=1}^n |v_i|$ true?
18451
Why does "$(( ~33 ))" produce -34?
32760
Is $\mathbf{Q}(\sqrt{2}, \sqrt{3}) = \mathbf{Q}(\sqrt{2}+\sqrt{3})$?
19
Why is the square root of a sum not equal to the square root of each its addends?
59442
Are there $a,b>1$ with $a^4\equiv 1 \pmod{b^2}$ and $b^4\equiv1 \pmod{a^2}$?
40532
Seems that I just proved $2=4$.
1522
Is $\sqrt{64}$ considered $8$? or is it $8,-8$?
83542
A natural problem in $\textrm{S}_2^\textrm{P}$?