1.Let F be an extension field of K and let u be in F. Show that K(a^2)contained in K(a) and [K(u):K(a^2)]=1 or 2.
2.Let F be an extension field of K and let a be in F be algebraic over K with minimal polynomial m(x). Show that if degm(x) is odd then K(u)=K(a^2).
1.I was thinking of looking at [K(u):K(a)][K(a):K(a^2)]
2.Well I know if a, is algebraic, then there exists a minimal polynomial m(x) such that m(a)=0. The degrees is what confuses me