Definitions of both:
Hamiltonian Circuit: Visits each vertex exactly once and consists of a cycle. Starts and ends on same vertex.
Eulerian Circuit: Visits each edge exactly once. Starts and ends on same vertex.
Is it possible a graph has a hamiltonian circuit but not an eulerian circuit?
Here is my attempt based on proof by contradiction:
Suppose there is a graph G that has a hamiltonian circuit. That means every vertex has at least one neighboring edge. <-- stuck