Subgroups of the dihedral group D6

In summary, the conversation discusses the dihedral group $D_6$ and its subgroups of different orders. The subgroups of order 2 are $\langle \tau \rangle$, $\langle \sigma\tau\rangle$, $\langle\sigma^2\tau\rangle$, $\langle\sigma^3\tau\rangle$, $\langle\sigma^4\tau\rangle$, $\langle\sigma^5\tau\rangle$, and $\langle\sigma^3\rangle$. The subgroups of order 3 are $\langle\sigma^2\rangle$ and $\langle\sigma^4\rangle$, and the subgroups of order 6 are $\langle \sigma \rangle$, $\langle \sigma
  • #1
mathmari
Gold Member
MHB
5,049
7
Hey! :eek:

I want to make the diagram for the dihedral group $D_6$:

Subroups of order $2$ : $\langle \tau \rangle$, $\langle \sigma\tau\rangle$, $\langle\sigma^2\tau\rangle$, $\langle\sigma^3\tau\rangle$, $\langle\sigma^4\tau\rangle$, $\langle\sigma^5\tau\rangle$, $\langle\sigma^3\rangle$

Subgroups of order $3$ : $\langle\sigma^2\rangle$, $\langle\sigma^4\rangle$

Subgroups of order $6$ : $\langle \sigma \rangle$, $\langle \sigma^5\rangle$, $\langle\sigma^2, \tau\rangle$, $\langle\sigma^2, \sigma\tau\rangle$

Are there more for each order? (Wondering)

The subgroups of order $4$ are those that are isomorphic to $\mathbb{Z}_4$ or to $\mathbb{Z}_2\times\mathbb{Z}_2$, right? (Wondering)
There are no elements of order $4$, so there are no subgroups of order $\mathbb{Z}_4$, right? (Wondering)
Are the subgroups that are isomorphic to $\mathbb{Z}_2\times\mathbb{Z}_2$ the $\langle a,b\rangle$, for all $a, b$ the elemennt of order $2$
($a,b \in \{\tau, \sigma\tau, \sigma^2\tau , \sigma^3\tau , \sigma^4\tau, \sigma^5\tau , \sigma^3\}$ ) ? (Wondering)
 
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  • #2
mathmari said:
Hey! :eek:

I want to make the diagram for the dihedral group $D_6$:

Subroups of order $2$ : $\langle \tau \rangle$, $\langle \sigma\tau\rangle$, $\langle\sigma^2\tau\rangle$, $\langle\sigma^3\tau\rangle$, $\langle\sigma^4\tau\rangle$, $\langle\sigma^5\tau\rangle$, $\langle\sigma^3\rangle$

Subgroups of order $3$ : $\langle\sigma^2\rangle$, $\langle\sigma^4\rangle$

Subgroups of order $6$ : $\langle \sigma \rangle$, $\langle \sigma^5\rangle$, $\langle\sigma^2, \tau\rangle$, $\langle\sigma^2, \sigma\tau\rangle$

Are there more for each order? (Wondering)

Hey mathmari! (Smile)

I don't think there are more of order 2, 3, and 6.

Oh, and aren't $\langle\sigma^2\rangle$ and $\langle\sigma^4\rangle$ the same sub group?
And $\langle \sigma \rangle$ and $\langle \sigma^5\rangle$ as well? (Wondering)
The subgroups of order $4$ are those that are isomorphic to $\mathbb{Z}_4$ or to $\mathbb{Z}_2\times\mathbb{Z}_2$, right? (Wondering)
There are no elements of order $4$, so there are no subgroups of order $\mathbb{Z}_4$, right? (Wondering)
Are the subgroups that are isomorphic to $\mathbb{Z}_2\times\mathbb{Z}_2$ the $\langle a,b\rangle$, for all $a, b$ the elemennt of order $2$
($a,b \in \{\tau, \sigma\tau, \sigma^2\tau , \sigma^3\tau , \sigma^4\tau, \sigma^5\tau , \sigma^3\}$ ) ? (Wondering)

Yes and yes.
But suppose we pick $a= \tau, b=\sigma\tau$.
Doesn't that mean that $\sigma\tau\cdot \tau = \sigma$ is in the sub group as well?
But then, the whole group is generated! :eek:
 
  • #3
I like Serena said:
Oh, and aren't $\langle\sigma^2\rangle$ and $\langle\sigma^4\rangle$ the same sub group?
And $\langle \sigma \rangle$ and $\langle \sigma^5\rangle$ as well? (Wondering)

Ah ok... (Thinking)
I like Serena said:
But suppose we pick $a= \tau, b=\sigma\tau$.
Doesn't that mean that $\sigma\tau\cdot \tau = \sigma$ is in the sub group as well?
But then, the whole group is generated! :eek:

Are the subgroups of order $4$ the following?
$\langle \sigma^3, \sigma\tau\rangle, \langle \sigma^3, \sigma^2\tau\rangle, \langle \sigma^3, \sigma^3\tau\rangle$
(Wondering)
Do you know what command I have to use in Latex to make the diagram? (Wondering)
 
Last edited by a moderator:
  • #4
Yep.

You mean something like
[TIKZ][-stealth]
\node (id) at (0,0) {$\{1\}$};
\node (s1) at (-2,1) {$\langle\tau\rangle$};
\draw (id) to (s1);
[/TIKZ]
(Wondering)
 
  • #5
I like Serena said:
You mean something like
[TIKZ]
\node (id) at (0,0) {$\{1\}$};
\node (s1) at (-2,1) {$\langle\sigma\rangle$};
\draw (id) to (s1);
[/TIKZ]
(Wondering)

It doesn't appear anything to me:

View attachment 6231

(Wondering)
 

Attachments

  • latex.PNG
    latex.PNG
    1.7 KB · Views: 103
  • #6
mathmari said:
It doesn't appear anything to me:

(Wondering)

Something went wrong. I'll have to figure it out when I get home. (Wait)
 
  • #7
I like Serena said:
Something went wrong. I'll have to figure it out when I get home. (Wait)

Ok! (Wait)
 
  • #8
Using the following part:

Code:
  \node (one) at (0,2) {$\text{\foreignlanguage{english}{id}}$};
  \node (2a) at (-6,0) {$\langle\tau\rangle$};
  \node (2b) at (-4,0) {$\langle\sigma^3\rangle$}; 
  \node (2c) at (-2,0) {$\langle\sigma\tau\rangle$}; 
  \node (2d) at (0,0) {$\langle\sigma^2\tau\rangle$};
  \node (2e) at (2,0) {$\langle\sigma^3\tau\rangle$};
  \node (2f) at (4,0) {$\langle\sigma^4\tau\rangle$};
  \node (2g) at (6,0) {$\langle\sigma^5\tau\rangle$};
  \node (3) at (-5.5,-2) {$\langle\sigma^2\rangle=\langle\sigma^4\rangle$}; 
  \node (4a) at (0.5, -4) {$\langle\sigma^3,\sigma\tau\rangle$}; 
  \node (4b) at (3,-4) {$\langle\sigma^3,\sigma^2\tau\rangle$}; 
  \node (4c) at (5.5,-4) {$\langle\sigma^3,\sigma^3\tau\rangle$}; 
  \node (6a) at (-5, -6.5) {$\langle\sigma\rangle=\langle\sigma^5\rangle$}; 
  \node (6b) at (-2.5, -6.5) {$\langle\sigma^2,\tau\rangle$}; 
  \node (6c) at (3.5, -6.5) {$\langle \sigma^2,\sigma\tau\rangle$}; 
  \node (G) at (0, -8) {$D_6$}; 
  \draw (one) -- (2a) -- (4c) -- (G); 
  \draw (one) -- (2b) -- (4a) -- (G); 
  \draw (2b) -- (4b) -- (G); 
  \draw (2b) -- (4c); 
  \draw (one) -- (2c) -- (4a); 
  \draw (one) -- (2d) -- (4b); 
  \draw (one) -- (2e) -- (4c); 
  \draw (one) -- (2f) -- (4a); 
  \draw (one) -- (2g) -- (4b); 
  \draw (one) -- (3) -- (6a) -- (G); 
  \draw (2b) -- (6a); 
  \draw (3) -- (6b) -- (G); 
  \draw (3) -- (6c) -- (G);

I get the following result:

View attachment 6232

Is this correct? (Wondering)

Or have I forgotten an arrow? (Wondering)
 

Attachments

  • D6.PNG
    D6.PNG
    14.2 KB · Views: 132
  • #9
It works again! (Happy)

\begin{tikzpicture}
%preamble \usepackage{amsmath}
%preamble \usetikzlibrary{shadows}
[very thick,
3dnode/.style 2 args={%
circle,
minimum size=1.2cm,
top color=#1!40!white,
bottom color=#1!60!black,
draw=#1!90!black,
thick,
general shadow={%
shadow xshift=.4ex, shadow yshift=-.4ex,
opacity=.5, fill=black!50,
}
}]
\node
at (-8,2) {Order \ 1};
\node[3dnode={orange}{}] (one) at (0,2) {$\text{id}$};
\node
at (-8,0) {Order \ 2};
\node[3dnode={green}{}] (2a) at (-6,0) {$\langle\tau\rangle$};
\node[3dnode={green}{}] (2b) at (-4,0) {$\langle\sigma^3\rangle$};
\node[3dnode={green}{}] (2c) at (-2,0) {$\langle\sigma\tau\rangle$};
\node[3dnode={green}{}] (2d) at (0,0) {$\langle\sigma^2\tau\rangle$};
\node[3dnode={green}{}] (2e) at (2,0) {$\langle\sigma^3\tau\rangle$};
\node[3dnode={green}{}] (2f) at (4,0) {$\langle\sigma^4\tau\rangle$};
\node[3dnode={green}{}] (2g) at (6,0) {$\langle\sigma^5\tau\rangle$};
\node
at (-8,-2) {Order \ 3};
\node[3dnode={green}{}] (3) at (-5.5,-2) {$\langle\sigma^2\rangle=\langle\sigma^4\rangle$};
\node
at (-8,-4) {Order \ 4};
\node[3dnode={green}{}] (4a) at (0.5, -4) {$\langle\sigma^3,\sigma\tau\rangle$};
\node[3dnode={green}{}] (4b) at (3,-4) {$\langle\sigma^3,\sigma^2\tau\rangle$};
\node[3dnode={green}{}] (4c) at (5.5,-4) {$\langle\sigma^3,\sigma^3\tau\rangle$};
\node
at (-8,-6.5) {Order \ 6};
\node[3dnode={green}{}] (6a) at (-5, -6.5) {$\langle\sigma\rangle=\langle\sigma^5\rangle$};
\node[3dnode={green}{}] (6b) at (-2.5, -6.5) {$\langle\sigma^2,\tau\rangle$};
\node[3dnode={green}{}] (6c) at (3.5, -6.5) {$\langle \sigma^2,\sigma\tau\rangle$};
\node
at (-8,-8) {Order 12};
\node[3dnode={blue}{},text=white] (G) at (0, -8) {$D_6$};
\draw (one) -- (2a) -- (4c) -- (G);
\draw (one) -- (2b) -- (4a) -- (G);
\draw (2b) -- (4b) -- (G);
\draw (2b) -- (4c);
\draw (one) -- (2c) -- (4a);
\draw (one) -- (2d) -- (4b);
\draw (one) -- (2e) -- (4c);
\draw (one) -- (2f) -- (4a);
\draw (one) -- (2g) -- (4b);
\draw (one) -- (3) -- (6a) -- (G);
\draw (2b) -- (6a);
\draw (3) -- (6b) -- (G);
\draw (3) -- (6c) -- (G);
\end{tikzpicture}

Shouldn't there be a couple more arrows to the subgroups of order 6? (Wondering)​
 
Last edited:
  • #10
Shouldn't there be an arrow from $\langle\tau\rangle$ to $\langle \sigma^2,\tau\rangle$? (Wondering)
 

FAQ: Subgroups of the dihedral group D6

What is the order of the dihedral group D6?

The order of D6 is 12, as it has 12 elements.

How many subgroups does D6 have?

D6 has 6 subgroups, which are the cyclic subgroups generated by each of its elements.

What is the structure of the subgroups of D6?

The subgroups of D6 have a cyclic structure, as they are generated by a single element. They can also be written as Zn, where n is the order of the subgroup.

What is the relationship between the subgroups of D6 and its elements?

Each element of D6 belongs to at least one subgroup, and each subgroup contains at least one element. However, not all elements belong to the same subgroup, and not all subgroups contain the same elements.

Can the subgroups of D6 be used to classify its elements?

Yes, the subgroups of D6 can be used to classify its elements into different conjugacy classes. Elements in the same subgroup are conjugate to each other, while elements in different subgroups are not conjugate.

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