Encyclopedia > Quadratic residue

  Article Content

Quadratic residue

In mathematics, a number q is called a quadratic residue modulo p if there exists an integer x such that:

<math>{x^2}\equiv{q}\mbox{ (mod }p\mbox{)}.</math>

Otherwise, q is called a quadratic non-residue.

In effect, a quadratic residue modulo p is a number that has a square root in modular arithmetic when the modulus is p. The Law of quadratic reciprocity says something about quadratic residues and primes.

Quadratic residues are used in the Legendre symbol.

External Links



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Islip Terrace, New York

... 3.21 and the average family size is 3.51. In the town the population is spread out with 29.5% under the age of 18, 6.7% from 18 to 24, 33.6% from 25 to 44, 20.6% from 45 ...

 
 
 
This page was created in 46.8 ms