1.II.10G

Groups, Rings and Modules
Part IB, 2007

(i) State a structure theorem for finitely generated abelian groups.

(ii) If KK is a field and ff a polynomial of degree nn in one variable over KK, what is the maximal number of zeroes of ff ? Justify your answer in terms of unique factorization in some polynomial ring, or otherwise.

(iii) Show that any finite subgroup of the multiplicative group of non-zero elements of a field is cyclic. Is this true if the subgroup is allowed to be infinite?