Show the dihedral group ##D_6## is isomorphic to ##S_3 x Z_2##

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The discussion focuses on demonstrating the isomorphism between the dihedral group D_6 and the direct product S_3 x Z_2. Participants emphasize the importance of understanding the orders of elements in both groups, noting that D_6 has 12 elements, matching the total in S_3 x Z_2. There is a suggestion to represent S_3 using permutations for clarity and to maintain consistency in group operations across the groups. Establishing a correspondence between the elements of D_6 and S_3 x Z_2 while preserving their orders is highlighted as a crucial step. The conversation underscores the need for a clear approach to tackle the problem effectively.
Robb
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Homework Statement
Show that the dihedral group ##D_6 is isomorphic to ##S_3 x Z_2## by constructing an explicit isomorphism. ( Hint: Color every other vertex of a hexagon red. Which elements of ##D_6## permute these 3 vertices. Also, which elements are order 2?)
Relevant Equations
##S_3 = { e, f, g, f^2, gf, gf^2 }##
##Z_2 = { 0,1 }##
##D_6 = { e, r, r^2, r^3, r^4, r^5, s, sr, sr^2, sr^3, sr^4, sr^5 }##
##f^3 = e##
##g^2 = e##
I'm not really sure where to begin with this problem. Any insight as to where to begin or what to look out for would be much appreciated!

Orders of ##S_3##
##|e|=1##
##|f|=3##
##|f^2|=2##
##|g|=2##
##|gf|=2##
##|gf^2|=3##

Orders of ##Z_2##
##|0|=1##
##|1|=2##

Orders of ##S_3 x Z_2##
##|e,0|=1##
##|e,1|=2##
##|f,0|=2##
##|f,1|=2##
##|f^2,0|=2##
##|F^2,1|=6##
##|g,0|=2##
##|g,1|=6##
##|gf,0|=3##
##|gf,1|=2##
##|gf^2,0|=2##
##|gf^2,1|=2##

Orders of ##D_6##
##|e|=1##
##|r|=6##
##|r^2|=3##
##|r^3|=2##
##|r^4|=3##
##|r^5|=6##
##|s|=2##
##|sr|=2##
##|sr^2|=2##
##|sr^3|=2##
##|sr^4|=2##
##|sr^5|=2##
 
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What is ##D_6##? I'm asking since there are various definitions for it. The coloring hint indicates it is the symmetry group of a hexagon, the representation you gave under Relevant Equations indicates that you can use generators and relations, too.

Furthermore I would write ##S_3## explicitly with permutations rather than with ##e,f,g##, but that's only a side note. ##S_3=\langle e,f,g\,|\,e=f^3=g^2 \rangle## works as well. I also would choose only one group operation. As you have chosen the multiplication for ##D_6## and ##S_3##, let's do the same with ##\mathbb{Z}_2=\{\,-1,+1\,\}##.

Now ##S_3 \times \mathbb{Z}_2## as a set are all pairs ##(\sigma,\varepsilon)## with ##\sigma\in S_3## and ##\varepsilon \in \mathbb{Z}_2##. These are ##12## pairs total, same as ##12## elements you listed for ##D_6##. Have you tried to establish a correspondence between them? And if possible by keeping the orders of the elements!
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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