I am currently studying Number Theory at the undergraduate level. In my textbook, I have come across the following question:
Show that if p is an odd prime and n is a positive integer, then there is a primitive root of $p^n$. Hint: suppose g is a primitive root of $p^k$. Use the equation we proved in problem 4* to show that either g or g+p is a primitive root of pk+1.
*equation 4 is: (g+p)$\Phi$($p^k$) $\equiv$ g$\Phi$($p^k$) - $p^k$g$\Phi$($p^k$)-1 (mod pk+1).
I am completely lost on this problem, so any help would be very appreciated.