Maximal real subfield of the eleventh cyclotomic field
= Maximal real subfield of the eleventh cyclotomic field
{title2=$\mathbb Q(\zeta_{11}+\zeta_{11}^{-1})$}
The fixed field of complex conjugation in $\mathbb Q(\zeta_{11})$ is the degree-five field $\mathbb Q(\zeta_{11}+\zeta_{11}^{-1})$.