What can you say about the value of n(p-1)/2 mod p for p an odd prime?
It is always 1
It is always -1
It is always 1 or -1
No, 2(5-1)/2 = -1 mod 5.
No, 4(5-1)/2 = 1 mod 5.
Correct.
What can you say about the value of n(p-1)/2 mod p for p an odd prime?
It is always 1
It is always -1
It is always 1 or -1