Does the graph G with varying vertex degrees have an Eulerian path?

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Discussion Overview

The discussion revolves around whether a graph G with a specified set of vertex degrees can possess an Eulerian path. Participants explore the implications of the vertex degrees and the conditions under which an Eulerian path exists, considering both theoretical and assignment-related contexts.

Discussion Character

  • Debate/contested
  • Homework-related
  • Conceptual clarification

Main Points Raised

  • Some participants assert that G can have an Eulerian path if it has either 0 or 2 vertices with odd degrees, even if some vertices have a degree of 0.
  • Others challenge this by questioning the validity of the vertex degree set {5, 1, 0, 6, 2}, suggesting that such a graph cannot exist.
  • A participant expresses confusion regarding the definition of an Eulerian path, noting that it must pass through all edges exactly once.
  • There are claims that the argument for the existence of an Eulerian path is not adequately established by the conditions presented.
  • Some participants emphasize the need for clarity in the definitions and conditions related to Eulerian paths and the specific graph in question.

Areas of Agreement / Disagreement

Participants generally disagree on the existence of a graph with the specified vertex degrees and the implications for the existence of an Eulerian path. The discussion remains unresolved regarding the validity of the conditions for an Eulerian path in the context of the given degrees.

Contextual Notes

There is uncertainty regarding the feasibility of a graph with the specified degrees, which may affect the discussion about Eulerian paths. Participants highlight the importance of definitions and the conditions under which Eulerian paths can exist.

Joystar77
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Let G be a graph with vertex set V = {v1, v2, v3, v4, v5}.

If the degrees of the vertices are 5, 1, 0, 6, 2, respectively, does G have an Eulerian path? Why or why not?

2E= deg v1 + deg v2 + deg v3 + deg v4 + deg v5

2E = 5 + 1 + 0 + 6 + 2

2E = 14

E = 7

Is it correct to say that G does have an Eulerian path because it can happen if the graph has either 0 or 2 vertices with odd degrees? Even an incomplete graph with the degree of 0 at one or more vertices can have an Eulerian path.

Is it correct to say that G doesn't have an Eulerian path because the path is suppose to pass through all edges exactly once?
 
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Joystar1977 said:
Let G be a graph with vertex set V = {v1, v2, v3, v4, v5}.

If the degrees of the vertices are 5, 1, 0, 6, 2, respectively, does G have an Eulerian path? Why or why not?

2E= deg v1 + deg v2 + deg v3 + deg v4 + deg v5

2E = 5 + 1 + 0 + 6 + 2

2E = 14

E = 7

Is it correct to say that G does have an Eulerian path because it can happen if the graph has either 0 or 2 vertices with odd degrees? Even an incomplete graph with the degree of 0 at one or more vertices can have an Eulerian path.
I don't understand your argument here. Can you restate this?

Joystar1977 said:
Is it correct to say that G doesn't have an Eulerian path because the path is suppose to pass through all edges exactly once?
This is not an argument which establishes the inexistence of an Eulerian path in the graph.

I think that there is no graph on five vertices which has 5, 1, 0, 6, 2 as the degrees of its vertices. So it doesn't make sense to ask if there is an Eulerian path in such a Graph.
 
This is a question for one of my problems on my assignment and states the following:

Let G be a graph with vertex set V = {v1, v2, v3, v4, v5}.

If the degrees of the vertices are 5, 1, 0, 6, 2, respectively, how many edges are in G?

I was told that an Eulerian path is a path which passes all edges exactly once. This can happen if the graph has either 0 or 2 vertices with odd degrees. Even an incomplete graph (with degree 0 at one or more vertices) can have an Eulerian path.

My question was that is it correct to say the following:

G does have an Eulerian path because it can take place even if the graph has 0 or many vertices to where you end up with an odd degree?

I don't want to confuse myself any more than what I already am with this problem.
Quote Originally Posted by Joystar1977 View Post
Is it correct to say that G doesn't have an Eulerian path because the path is suppose to pass through all edges exactly once?

caffeinemachine said:
I don't understand your argument here. Can you restate this?This is not an argument which establishes the inexistence of an Eulerian path in the graph.

I think that there is no graph on five vertices which has 5, 1, 0, 6, 2 as the degrees of its vertices. So it doesn't make sense to ask if there is an Eulerian path in such a Graph.
 
Joystar1977 said:
This is a question for one of my problems on my assignment and states the following:

Let G be a graph with vertex set V = {v1, v2, v3, v4, v5}.

If the degrees of the vertices are 5, 1, 0, 6, 2, respectively, how many edges are in G?

I was told that an Eulerian path is a path[/color] which passes all edges exactly once. This can happen if the graph has either 0 or 2 vertices with odd degrees. Even an incomplete graph (with degree 0 at one or more vertices) can have an Eulerian path.

My question was that is it correct to say the following:

G does have an Eulerian path because it can take place even if the graph has 0 or many vertices to where you end up with an odd degree?[/color]

I don't want to confuse myself any more than what I already am with this problem.
About the thing marked in red.. An Eulerian path is not a path! An Eulerian path is a trail, in general, which contains each edge exactly once.

Its true that if a connected Graph has zero or two odd vertices then it has an Eulerian Path. But here the problem is that there is no (simple) graph on $5$ vertices which has 5,1,0,6,2 as the degrees of its vertices. So the question in meaningless.

About the thing marked in blue. I don't understand what you are trying to say here. You may need to rephrase that.
 

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