3. Exercise §5.2 #12. Let p be an odd prime number. (a) Prove that any primitive root r modulo p is a quadratic nonresidue modulo p. Deduce that r-1)/2 = -1 mod p (b) Prove that there are exactly - (p...

Plz answer both parts and gets thumbup

Extracted text: 3. Exercise §5.2 #12. Let p be an odd prime number. (a) Prove that any primitive root r modulo p is a quadratic nonresidue modulo p. Deduce that r-1)/2 = -1 mod p (b) Prove that there are exactly - (p – 1) incongruent quadratic nonresidues modulo p that are not primitive roots modulo p