Exercise
Suppose p is a prime number.
What is the value of 
(p2)?
p2 - 1
p2 - p - 1
p2 - p
No.
No.
Yes, apply the formula, using (p) = p - 1,
(1) = 1.
(p) = p - 1,
(1) = 1.
Exercise
Suppose p is a prime number.
What is the value of (p2)?
p2 - 1
p2 - p - 1
p2 - p
(p) = p - 1,
(1) = 1.