# Math Help - roots

1. ## roots

I know a primitive root exist if m=1,2,4,p,2p.

for m=10, can i say that 3 is a primitive root since 3^4 is congruent to 1 where 4 =phi(10).

2. ## Re: roots

Yes, this is true because φ(10) is the smallest power that makes 3r $\equiv 1$mod 10