For each and in define a function by

The set of all such function forms a group with the group multiplication given by the compostion of the functions.(Not need to verify is a group)

a. Determine and find . Hence show that is non-abelian.

b. Show that ,given by , is a homomorphism.

I'm OK with the part but I forget how to show .

Also for part b, I don't really get it.

Thank you for help