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

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SUMMARY

The discussion focuses on the group G consisting of six matrices: I, A, B, C, D, and K, with matrix multiplication as the operation. The function f: G → ℝ* defined by f(x) = det(x) reveals that the image of G includes the determinants 1 and -1. The kernel of f is identified as {I, B, D}, leading to the conclusion that there are two cosets in G/N: N and Na. The multiplication tables for G/N and Im(G) need to be completed based on these findings.

PREREQUISITES
  • Understanding of matrix operations and determinants
  • Familiarity with group theory concepts such as kernels and images
  • Knowledge of coset multiplication in group theory
  • Ability to compute matrix determinants
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  • Calculate the determinants of all matrices in G to confirm the image of G
  • Learn about constructing coset multiplication tables in group theory
  • Explore the properties of kernels and images in linear transformations
  • Study the implications of the determinant function in group theory
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Students and educators in linear algebra and abstract algebra, particularly those studying group theory and matrix operations.

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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