Test 2
( \newcommand{\kernel}{\mathrm{null}\,}\)
Consider the symmetric group S7.
- Factor the permutation (12345)(67)(1357)(613) into disjoint cycles.
- Identify all possible types of permutations and specify the quantity of each type.
- Find the possible order of all the elements of S7.
- Show that S7 is not abelian.
Consider the group Z12 with addition modulo 12.
- Is (Z12,+mod(12)) cyclic group? If so, what are the possible generators? How many distinct generators exist? What can you say about the number of generators, considering the Euler totient function, and the possible generators in relation to divisors?
- Let G=⟨g⟩ be a cyclic group with |g|=n. Then G=⟨gk⟩ if and only if gcd(k,n)=1.
- Find all subgroups of Z12 generated by each element. What are their respective orders? What can you say about these orders?
Consider the symmetric group S4.
- Find the centre of S4.
- If possible, find a cyclic subgroup of S4 with an order of 4.
- Find a non-cyclic subgroup of S4 with order 4 if possible.
Consider Z8 and the operation +mod8.
- Show that H={0,2,4,6} is a subgroup of Z8.
- List the left and right cosets of H={0,2,4,6} in Z8.
Consider D4={e,a,a2,a3,b,ab,a2b,a3b} with a4=e,b2=e,ba=a3b.
- Show that Z(D4)={e,a2}. (Hint: Z(G)={x∈G|ax=xa,∀a∈G}.)
- List the left and right cosets of Z(D4), in D4.