Finding the image and completing multiplication tables for G/N and Im(G)

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Homework Help Overview

The discussion revolves around a group of six matrices and the exploration of their properties under matrix multiplication. The original poster is tasked with finding the image of a function defined on these matrices and completing coset multiplication tables for the quotient group G/N and the image of G.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the determination of the image of the group G and the calculation of the determinant for each matrix. There is uncertainty about how to define the range and complete the multiplication tables for G/N and Im(G).

Discussion Status

Some participants have begun calculating the determinants and identifying elements of the image, while others are seeking clarification on how to structure the coset multiplication tables. There is an acknowledgment of the kernel of the function, but the completion of the tables remains a point of inquiry.

Contextual Notes

Participants note that the kernel of the function is {I, B, D}, and there is a suggestion to calculate f(x) for each matrix to aid in identifying the image. The original poster expresses uncertainty about the setup of the multiplication tables.

The_Iceflash
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Homework Statement


Consider this group of six matrices:

Let G = {I, A, B, C, D, K}, Matrix Multiplication>

I =\begin{bmatrix}1 & 0\\0 & 1\end{bmatrix} A =\begin{bmatrix}0 & 1\\1 & 0\end{bmatrix} B =\begin{bmatrix}0 & 1\\-1 & -1\end{bmatrix}

C =\begin{bmatrix}-1 & -1\\0 & 1\end{bmatrix} D =\begin{bmatrix}-1 & -1\\1 & 0\end{bmatrix} K =\begin{bmatrix}1 & 0\\-1 & -1\end{bmatrix}

Operation Table for this group:

_|I A B C D K
I |I A B C D K
A|A I C B K D
B|B K D A I C
C|C D K I A B
D|D C I K B A
K|K B A D C I

Define f:G\rightarrow \left\langle\(R^{*}, \bullet\right\rangle by f(x) = det(x) for any Matrix x \in G.

Questions:

List all the elements in the image of G?

Complete coset multiplication tables for G/N (N being the Ker(f)) and Im(G) (a subgroup of <R*, \bullet>

Homework Equations


N/A

The Attempt at a Solution



I know the image of G is the range. I'm not exactly sure what to consider the range.

For the multiplication tables I know I'm to set it up like this but I'm not sure how to complete them. I appreciate any help. I do know that the Ker(f) is {I, B, D}.

G/N:
_|_______
|
|
|

Image(G):
_|_________
|
|
|
 
Last edited:
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The_Iceflash said:

Homework Statement


Consider this group of six matrices:

Let G = {I, A, B, C, D, K}, Matrix Multiplication>

I =\begin{bmatrix}1 &amp; 0\\0 &amp; 1\end{bmatrix} A =\begin{bmatrix}0 &amp; 1\\1 &amp; 0\end{bmatrix} B =\begin{bmatrix}0 &amp; 1\\-1 &amp; -1\end{bmatrix}

C =\begin{bmatrix}-1 &amp; -1\\0 &amp; 1\end{bmatrix} D =\begin{bmatrix}-1 &amp; -1\\1 &amp; 0\end{bmatrix} K =\begin{bmatrix}1 &amp; 0\\-1 &amp; -1\end{bmatrix}

Operation Table for this group:

_|I A B C D K
I |I A B C D K
A|A I C B K D
B|B K D A I C
C|C D K I A B
D|D C I K B A
K|K B A D C I

Define f:G\rightarrow \left\langle\(R^{*}, \bullet\right\rangle by f(x) = det(x) for any Matrix x \in G.

Questions:

List all the elements in the image of G?

Complete coset multiplication tables for G/N (N being the Ker(f)) and Im(G) (a subgroup of <R*, \bullet>

Homework Equations


N/A

The Attempt at a Solution



I know the image of G is the range. I'm not exactly sure what to consider the range.

For the multiplication tables I know I'm to set it up like this but I'm not sure how to complete them. I appreciate any help. I do know that the Ker(f) is {I, B, D}.

G/N:
_|_______
|
|
|

Image(G):
_|_________
|
|
|

For the first part, go through all six matrices and calculate f(x) for each of them. For example, f(A) = -1.
 
So, the f(x)'s i receive are 1 and -1. Oh so that's what my image should be. I get that now. Thanks.
 
Any help on the tables from anyone would be greatly appreciated.

This is what I'm thinking for the G/N table:

__|N Na
N| N Na
Na| Na N

I found only 2 cosets and one is the Kernel and the other one I called Na due to a being one of the elements in it.
 

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