Let p be a prime such that p is congruent to 3 modulo 4 and let a be a quadratic residue modulo p. Prove that if ab is congruent to p-1 modulo p, then b is a quadratic non-residue modulo p.
Let p be a prime such that p is congruent to 3 modulo 4 and let a be a quadratic residue modulo p. Prove that if ab is congruent to p-1 modulo p, then b is a quadratic non-residue modulo p.