Difference between revisions of "Quadratic Reciprocity Theorem"

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<math>\left(\frac{p}{q}\right)\left(\frac{q}{p}\right)=(-1)^{\frac{p-1}{2}\frac{q-1}{2}}</math>
 
<math>\left(\frac{p}{q}\right)\left(\frac{q}{p}\right)=(-1)^{\frac{p-1}{2}\frac{q-1}{2}}</math>
  
 
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==Links==
[http://www.artofproblemsolving.com/Wiki/index.php/Quadratic_residues]
+
Quadratic Residues[http://www.artofproblemsolving.com/Wiki/index.php/Quadratic_residues]
  
  
 
[[Category:Number theory]]
 
[[Category:Number theory]]

Revision as of 20:59, 10 October 2011

Quadratic reciprocity is a classic result of number theory.
It is one of the most important theorems in the study of quadratic residues.

It states that $\left(\frac{p}{q}\right)= \left(\frac{q}{p}\right)$ for primes $p$ and $q$ greater than $2$ where both are not of the form $4n+3$ for some integer $n$.
If both $p$ and $q$ are of the form $4n+3$, then $\left(\frac{p}{q}\right)= -\left(\frac{q}{p}\right)$

Another way to state this is:
$\left(\frac{p}{q}\right)\left(\frac{q}{p}\right)=(-1)^{\frac{p-1}{2}\frac{q-1}{2}}$

Links

Quadratic Residues[1]