On Thursday, January 24, 2013 2:20:15 PM UTC+1, Timothy Murphy wrote: > Rupert wrote: > > > > > Does anyone know where I can find a proof that, given a separable > > > quadratic extension of a field of characteristic two, the trace map is > > > surjective? > > > > I may have misunderstood the question, but isn't > > > > tr(ac) = a tr(c) > > > > if a is in the ground-field and c in the extension field? > > So if the trace was not surjective, it would have to be identically zero, > > which I think it is easy to see is not the case. > > (Eg if c has minimal equation f(x) = 0 the trace is the x coefficient.) >
Sounds fair enough. Thanks. Being a bit slow today.