What is the First Isomorphism Theorem?

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Homework Help Overview

The discussion revolves around the First Isomorphism Theorem in group theory, focusing on the concepts of homomorphisms, kernels, images, and normal subgroups.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants are attempting to clarify the theorem's statement and its components, such as the definitions of homomorphism, isomorphism, and normal subgroup. Questions are raised about the meaning of specific terms and the implications of the theorem.

Discussion Status

The discussion is ongoing, with some participants seeking clarification on the definitions and implications of the theorem. There is an indication that not all participants share the same understanding of the terminology involved.

Contextual Notes

Some participants express the need for clearer definitions and explanations, suggesting that prior knowledge may vary among contributors.

proplaya201
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Homework Statement



can someone explain the 1st isomorphism theorem to me(in simple words) i really don't get it

Homework Equations





The Attempt at a Solution

 
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Why don't you write down the 1st isomorphism theorem, so people here will actually know what are you talking about. Not everybody might have learned that theorem adressed with the same name as you!
 
If G and H are groups and f is a homomorphism from G to H, then the kernel K of f is a normal subgroup of G, the image of f is a subgroup of H, and the quotient group G /K is isomorphic to the image of f.
 
If f: G-> H, then

The kernel, K, of f is a subgroup of G - {x in G such that f(G)= eH}

The Image, I, of f is a subgroup of H- {y in H such that y= f(x) for some x in G}

1) K is a normal subgroup of G.

2) G/K is isomorphic to I.

Do you understand what "homomorphism" and "isomorphism" mean? Do you understand what a "normal subgroup" is and what "G/K" is?
 
can you specify G/K is isomorphic to I.
 

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