Binary Relations and Equivalence Relations

Binary Relations and Equivalence Relations

Explores binary relations on sets, relation properties (reflexive, symmetric, transitive), equivalence relations, and partitions. Covers composition of relations, inverse relations, and how relations connect to graphs with directed edges and multigraphs.

Graph Coloring – Chromatic Number and Index

Graph Coloring – Chromatic Number and Index

Comprehensive study of graph vertex coloring and edge coloring. Covers chromatic number, Four Color Theorem for planar graphs, chromatic index, clique numbers, Brooks’ Theorem, and Vizing’s Theorem with applications to scheduling and map coloring.

Euler Trails, Circuits, and Hamilton Paths

Euler Trails, Circuits, and Hamilton Paths

Covers Euler trails and circuits (traversing every edge exactly once) with necessary and sufficient conditions based on vertex degrees. Contrasts with Hamilton paths (visiting every vertex exactly once) and discusses the NP-complete nature of Hamilton path problems.

Planar Graphs and Euler’s Formula

Planar Graphs and Euler’s Formula

Study of planar graphs, Euler’s formula (v-e+f=2), and applications to polyhedra. Proves K5 and K3,3 are non-planar, discusses faces, and applies Euler’s formula to regular polyhedra including tetrahedron, cube, and dodecahedron.