Group Theory 20 - Lagrange's Theorem -2

We prove that any finite group of prime order is cyclic and give a few application. We then show that A4 is group of order 12 but it does not have subgroup of order 6. This proves that the converse of Lagrange's theorem is l false.On the way we count the number of k-cycles in Sn. Music: Bensound.com License code: QCP9W9JHHR9ZEZQO Artist: : Benjamin Tissot