Paper 3, Section II, D
Part IA, 2018
Let be an element of a group . We define a map from to by sending to . Show that is an automorphism of (that is, an isomorphism from to ).
Now let denote the group of automorphisms of (with the group operation being composition), and define a map from to by setting . Show that is a homomorphism. What is the kernel of ?
Prove that the image of is a normal subgroup of .
Show that if is cyclic then is abelian. If is abelian, must be abelian? Justify your answer.