Hi all,
The question concerns que same subject as my previous post in this section, but I still didn't figure it out:
Let p be a prime number and a be an integer such that p does not divide a. Show that if then or .
Any tips or approach suggestions will be useful.
Thanks in advance,
Yes, I should have been more explicity why the last line holds. By the way, when I talk about instead of saying "it is a field and hence and integral domain" I perfer to say "it is an integral domain and hence a field". Why? Because there is a theorem, which I am sure you know but if not it is a nice result, that says if is a finite integral domain then is a field. Because I like this result I like to switch around the order of my statement. But whatever, I am getting off topic.