Question

Prove that if T is a tree with at least two vertices. Then T has at least two vertices of degree one.

Answer 1

@rational

Answer 2

hey still stuck on this ?

Answer 3

For proof strategy, consider attacking the contrapositive: assume the tree has no vertices of degree one (or rather, less than 2 vertices, so one or none), and establish that this implies that \(T\) contains at least one cycle, or is not connected.