i wish any one can hepl me with this problems

1) if p is prime , show that th product of the $\displaystyle \phi(p-1)$ primitive roots of p is congurent modulo p to$\displaystyle (-1)^\phi(p-1)$.

[hint: if r is primitive root of p , then r^k is primitive root of p provided that gcd(k,p-1)= 1 ]

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2) use the fact that each prime p has a primitive root to give a different proof of Wislon's theroem.

[hint : if p has a primitive root r, then (p-1)!=r^1+2+..+(p-1)(modp)]