Proving Homomorphism of Groups: Showing f(e)=e' and f(g^-1)=f(g)^-1

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In summary, the conversation discusses how to show that in a homomorphism, f(e) = e' and f(g^-1) = f(g)^-1. The attempt at a solution involves using the property of a neutral element and the homomorphism equation, but it is unclear how to show f(g^-1) = f(g)^-1. The questioner asks for clarification on the concept of f(gg^-1).
  • #1
LagrangeEuler
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Homework Statement


Show that
##f(e)=e'## and ##f(g^-1)=f(g)^-1##

Homework Equations


Homomorphism
f(x\cdot y)=f(x)\cdot f(y)

The Attempt at a Solution


I show the first one. Neutral element is element which satisfied
##e\cdot e=e##.
So
##f(e)=f(e\cdot e=e)=f(e)\cdot f(e)##
So ##f(e)=e'##.
But how to show
##f(g^{-1})=f(g)^{-1}##?
 
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  • #2
LagrangeEuler said:

Homework Statement


Show that
##f(e)=e'## and ##f(g^-1)=f(g)^-1##



Homework Equations


Homomorphism
f(x\cdot y)=f(x)\cdot f(y)



The Attempt at a Solution


I show the first one. Neutral element is element which satisfied
##e\cdot e=e##.
So
##f(e)=f(e\cdot e=e)=f(e)\cdot f(e)##
So ##f(e)=e'##.

But how to show
##f(g^{-1})=f(g)^{-1}##?

What is [itex]f(gg^{-1})[/itex]?
 
  • #3
Tnx.
 

1. What is a homomorphism of groups?

A homomorphism of groups is a function between two groups that preserves the group structure. This means that the operation in the first group is still valid in the second group.

2. What is the difference between a homomorphism and an isomorphism?

A homomorphism is a function that preserves the group structure, while an isomorphism is a bijective homomorphism. This means that an isomorphism not only preserves the group structure, but also preserves the elements and their relationships.

3. How do you determine if a function is a homomorphism of groups?

To determine if a function is a homomorphism of groups, you must check if it preserves the group operation. This means that for any two elements in the first group, their corresponding elements in the second group must also satisfy the group operation.

4. Can a homomorphism of groups be onto or one-to-one?

A homomorphism of groups can be either onto or one-to-one, or both. If the homomorphism is onto, it means that every element in the second group has at least one corresponding element in the first group. If the homomorphism is one-to-one, it means that each element in the second group has a unique corresponding element in the first group.

5. What is the kernel of a homomorphism?

The kernel of a homomorphism of groups is the set of elements in the first group that are mapped to the identity element in the second group. In other words, it is the set of elements that are mapped to the neutral element under the homomorphism.

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