1. Let G be a group of order 4. Prove that every element of G has order 1,2, or 4.
2. Classify groups of order 4 by considering the following two cases:
a. G contains an element of order 4
b. Every element of G has order <4
could anyone please help me to solve these problems?
and what does it mean by 'Classify groups of order 4'?