Answer to Question #27803 in Abstract Algebra for Andrew Fairbanks

Question

A. Use de Moivre’s formula to verify that the 5th roots of unity form a group under complex multiplication, showing all work.



B. Let F be a field. Let S and T be subfields of F.

1. Use the definitions of a field and a subfield to prove that S ∩ T is a field, showing all work.