Positive rationals satisfying: $a^2+a^2=c^2$?
6275
How can you prove that the square root of two is irrational?
23835
Discrete mathematics - Find all integer solutions of the equation $a^2+ b^2 + c^2=a^2 b^2$.
78309
On an expansion of $(1+a+a^2+\cdots+a^n)^2$
72670
Find three distinct triples (a, b, c) consisting of rational numbers that satisfy $a^2+b^2+c^2 =1$ and $a+b+c= \pm 1$.
125164
How to prove the existence of $b$ in $Q$ such that $a<b^2<c$ in $Q$?
20034
Does $a^2+b^2=1$ have infinitely many solutions for $a,b\in\mathbb{Q}$?
12079
A positive polynomial is the sum of two squares in $\mathbb{R}[X]$
61022
Diophantine Equations : Solving $a^2+ b^2=2c^2$
113168
If $a > b$, is $a^2 > b^2$?
133164
Rational solutions for $x^2+y^2=3$
41689
Find all solutions: $x^2 + 2y^2 = z^2$
72470
Prove that $2|ab| \leq a^2 + b^2$ and $|a|+|b| \leq \sqrt {2}(a^2+b^2)^{1/2}$
85449
Show a,b,c congruences when $a^2+b^2=c^2$
13914
If $a^2+b^2=c^2$ then $a$ or $b$ is even.
132098
Prove $(a^2+b^2)(c^2+d^2)\ge (ac+bd)^2$ for all $a,b,c,d\in\mathbb{R}$.
86285
Given positive integers $ x , y$ and that $3x^2 + x = 4y^2 +y$ Prove that $x-y$ is a perfect square
33105
Find the value of $a^2-b^2+c^2$