Question

Draw all non-isomorphic trees on 4 vertices. There are only 2 of them.

Answer 1

I don't understand the text for how to find the non-isomorphic trees for n vertices.

Answer 2

Do you feel like you have a good handle on what it means for two graphs to be isomorphic? I don't mean reciting the definition, but looking at two graphs and telling if they are isomorphic or not?

Answer 3

I know there are some things that make two graphs isomorphic...same degree sequence, if they are connected, same number of vertices and edges, and the labeling.

Answer 4

Isomorphic graphs are basically the same with the labels of the vertices rearranged. E.g:

So anyway, if you look at that tree on 3 vertices, you can see that there are two types of vertices. The middle and the end. This gives you a hint of how you can connect the 4th vertex.