How to Prove the Even Permutations in Sn Form a Group?

[dundalkhead]

Homework Statement

Prove that the set of even permutations in Sn (i.e, An) is a group.
List the elements of A4

Homework Equations

How do I even try to prove these

The Attempt at a Solution

I have started a new course and am finding the problems very difficult.
Is there any books out there that can help me on groups and permutations.
Any help would be great.
Thanks

 

[slider142]

You have to show that the elements of the set satisfy the axioms of a group under the group operation (which is not mentioned, but they probably mean combined permutation).