Path from Odd Degree Vertex in Simple Graph?

In summary, the conversation discusses the idea that in every simple graph, there is a path from any vertex of odd degree to another vertex of odd degree. This is because the sum of degrees of all vertices in a simple graph must be even, and if there is a vertex of odd degree, there must be another one to balance the sum. If the graph is connected, the path can be easily found, and even if it is not connected, the odd vertices still come in pairs in each connected subgraph. The statement to prove is that in a simple graph, if a vertex has odd degree, there is a path from that vertex to another vertex of odd degree.
  • #1
hyderman
28
0
please help me with this question

Show that in every simple graph there is a path from any vertex of odd
degree to some other vertex of odd degree?

here is my answer please check and correct if its wrong thanx

ANSWER:
In a simple graph, the sum of the degrees of the vertices must always be even. Thus, if there is a vertex of odd degree, there must be another vertex of odd degree (so the sum will be even). If the graph is connected, then there is a path from any vertex to any other vertex. If it is not connected, it must be made up of connected subgraphs, and the sum of the degrees of the vertices of each connceted subgraph still has to be even – so the odd vertices in each connected subgraph must still come in pairs.
 
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  • #2
sound ok to me...
 
  • #3
I think the "question" is badly phrased. For example, consider the graph consisting of one vertex. In this graph, there are no paths and no vertices of odd degree. The statement to prove should be this: Let G be a simple graph and v a vertex in G. If v has odd degree, then there is a path from v to u where u is a vertex of odd degree. You can prove this using contradiction and the fact that the sum of the degrees of all the vertices is even which you used in the first post.
 

FAQ: Path from Odd Degree Vertex in Simple Graph?

What is a simple graph?

A simple graph is a mathematical representation of a network, where the connections between vertices (or nodes) are represented by edges. In a simple graph, there are no self-loops or multiple edges between the same pair of vertices.

What is a vertex of odd degree?

A vertex of odd degree is a vertex in a graph that is connected to an odd number of other vertices through edges. In other words, it has an odd number of edges incident to it.

How do you prove that there is a path from any vertex of odd degree to another vertex of odd degree in a simple graph?

This can be proven using the concept of Eulerian paths and circuits. Every simple graph has an Eulerian path or circuit, which is a path or circuit that visits every edge exactly once. Since the degrees of the vertices in a simple graph must be even for an Eulerian path or circuit to exist, any vertex with an odd degree must have at least one edge connecting it to another vertex with an odd degree.

Can there be more than one path between two vertices of odd degree in a simple graph?

Yes, there can be more than one path between two vertices of odd degree in a simple graph. As long as there is at least one edge connecting the two vertices, there can be multiple paths between them. However, there must be at least one path between them for the statement to hold true.

Is this statement true for all types of graphs?

No, this statement is only true for simple graphs. In other types of graphs, such as directed graphs or multigraphs, there may not be a path between two vertices of odd degree. In fact, in directed graphs, the concept of odd and even degrees does not apply in the same way as it does in undirected graphs.

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