1. ## isomorphism

1. Prove that the products ab and ba are conjugate elements in a group

2. prove that the set Aut G of automorphism of a group G forms a group, the law of composition being composition of functions

2. 1. Multiply $\displaystyle ab$ on the left by $\displaystyle a^{-1}$ and on the right by $\displaystyle a$ and you get …?
2. Verify all the group axioms for $\displaystyle \mathrm{Aut}(G).$