##  [Quadratic Residue](/quadratic-residue) 

  ##  [Quadratic Residue](https://puremath.quantumdictionary.io/quadratic-residue-0) 

  

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- Mathematics & Logic -

**Pure Mathematics Dictionary**

 







 

 

 

 



 

 

 

 

Definition

An integer r is a quadratic residue modulo n if there exists an integer x such that x^2 ≡ r (mod n); otherwise r is a quadratic nonresidue modulo n. Residues are considered as classes modulo n.