The sum of square roots of non-perfect squares is never integer
22800
Can $\sqrt{n} + \sqrt{m}$ be rational if neither $n,m$ are perfect squares?
115454
Primality test bound: square root of n
53244
Prove that $p \in \mathbb{R}[x]$ can be represented as a sum of squares of polynomials from $\mathbb{R}[x]$
29799
Sum of four squares not a prime
19588
$n!+1$ being a perfect square
149481
Number theory counting sums of squares modulus
135458
When is a sum of consecutive squares equal to a square?
97952
Square root of 1 is (not) -1
39170
Existence of square root
57250
Proving that the sum and difference of two squares (not equal to zero) can't both be squares.
100913
It is impossible for $(x-1)^2+x^2+(x+1)^2$ to be a perfect square
147666
How to prove that either $2^{500} + 15$ or $2^{500} + 16$ isn't a perfect square?
145558
Prove that $2^n+3^n $ is never a perfect square
53331
$\mathbb{Q}(\sqrt2, \sqrt3)$ is not isomorphic to $\mathbb{Q}(\sqrt[4]2)$
118036
Proving at least 99 pairwise sums of the reals are non-negative
121469
Proof of observations on natural numbers being expressed as differences of squares.
126199
Proof of $\pi$ not being a quadratic irrational number.