Let p be an odd prime and b be a quadratic residue of p.
For p=19 for which pâ?¡3 (mod 4), show by direct calculation that the pairs 1 and 18, 2 and 17, 3 and 16, and so on, have one quadratic residue and one quadratic nonresidue.
QR: Quadratic residue
QNR: Quadratic nonresidue
Quadratic Residue is contextualized.