chapter1:1.4

It helps in interpreting data visually and making informed decisions.

It is only useful for drawing pictures.

It is not relevant to real-world problems.

It is mainly used for artistic purposes.

Bev, Cai, Flo

Ana, Dan, Ed

Hal, Gia, Ira

Ed, Dan, Hal

Parallel edges

Loops

Isolated vertices

Vertices with no edges

Vertices are the dots and edges are the lines connecting them.

Edges are the dots and vertices are the lines connecting them.

Graphs always represent equations.

Vertices can never be connected to themselves.

An edge connecting two different vertices

An edge connecting a vertex to itself

Two edges connecting the same pair of vertices

A vertex with no incident edges

They connect the same pair of endpoints

They are incident on the same vertex

They form a loop

They are adjacent to each other

v4 is an isolated vertex

e2 and e3 are parallel edges

e6 and e7 are loops

v1 is adjacent to v4

e2 and e3

e1 and e4

e1 and e2

e3 and e4

{v1, v2, v3, v4}

{v1, v2, v3, v4, v5}

{e1, e2, e3, e4}

{v1, v2, v3}

e1: {v1, v2}, e2: {v2, v3}, e3: {v3, v4}, e4: {v4, v5}, e5: {v5, v1}

e1: {v1, v3}, e2: {v2, v4}, e3: {v2, v4}, e4: {v3}, e5: {v1, v2}

e1: {v1, v2}, e2: {v2, v4}, e3: {v3, v5}, e4: {v4, v1}, e5: {v5, v3}

e1: {v1, v2}, e2: {v2, v3}, e3: {v3, v1}, e4: {v4, v5}, e5: {v5, v4}

Telephone systems

Electric power systems

Gas pipeline systems

All of the above

Edges are associated with ordered pairs of vertices.

Each edge has endpoints.

Edges are always bidirectional.

A directed edge goes from one vertex to another.

Each edge is associated with an unordered pair of vertices.

Each edge is associated with an ordered pair of vertices.

Directed graphs cannot have endpoints.

Directed graphs are the same as undirected graphs.