KnowraQuadratic residueLinked fromLinked fromThe 12 pages that link to Quadratic residue, each with the reason it gives.All 12Broader topic 2Related 4Narrower topic 6Fermat's theorem on sums of two squaresRelated: A representation p=a²+b² forces −1 to be a square modulo p when b is nonzero.Solovay–Strassen primality testRelated: The Jacobi symbol encodes quadratic-residue information that underlies the comparison.Legendre's three-square theoremRelated: Squares modulo 8 restrict sums of three squares and expose the obstruction at numbers congruent to 7.Artin's conjecture on primitive rootsRelated: Squares cannot generate all nonzero classes modulo odd primes.