1.I.1B

Algebra and Geometry
Part IA, 2003

(a) Write the permutation

(123)(234)(123)(234)

as a product of disjoint cycles. Determine its order. Compute its sign.

(b) Elements xx and yy of a group GG are conjugate if there exists a gGg \in G such that gxg1=y.g x g^{-1}=y .

Show that if permutations xx and yy are conjugate, then they have the same sign and the same order. Is the converse true? (Justify your answer with a proof or counterexample.)