Find a primitive root, for all positive integral m, modulo each integer below. (a) 7 (Hint: Using Corollary 5.15, find a common primitive root r modulo 7 and 72. The proof of Proposition 5.17 then guarantees that r is a primitive root modulo 7" for all positive integral m.) (b) 11m (c) 13m (d) 17m
