proof that every group of prime order is cyclic

Let p be a prime and G be a group such that |G|=p. Then G contains more than one element. Let g∈G such that g≠eG. Then ⟨g⟩ contains more than one element. Since ⟨g⟩≤G, by Lagrange’s theorem, |⟨g⟩| divides p. Since |⟨g⟩|>1 and |⟨g⟩| divides a prime, |⟨g⟩|=p=|G|. Hence, ⟨g⟩=G. It follows that G is cyclic.

Title proof that every group of prime order is cyclic
Canonical name ProofThatEveryGroupOfPrimeOrderIsCyclic
Date of creation 2013-03-22 13:30:55
Last modified on 2013-03-22 13:30:55
Owner Wkbj79 (1863)
Last modified by Wkbj79 (1863)
Numerical id 7
Author Wkbj79 (1863)
Entry type Proof
Classification msc 20D99
Related topic ProofThatGInGImpliesThatLangleGRangleLeG