Hi,

my question is, "for n = 3 or greater, show is trivial if n is odd and is {1, } if n is even."

Any help would be appreciated; we haven't learned anything advanced in class yet, just about cosets and lagrange's thm.

My initial attempt was to consider that if is in , then for all g.

if g=a then and if g=b

but from here I'm quite stuck.

Thanks!!