# quadratic residue

Let $a,n$ be relatively prime integers. If there exists an integer $x$ that satisfies

 $x^{2}\equiv a\pmod{n}$

then $a$ is said to be a quadratic residue of $n$. Otherwise, $a$ is called a quadratic nonresidue of $n$.

Title quadratic residue QuadraticResidue 2013-03-22 11:55:19 2013-03-22 11:55:19 mathcam (2727) mathcam (2727) 9 mathcam (2727) Definition msc 11A15 LegendreSymbol EulersCriterion quadratic non-residue quadratic nonresidue