discrete maths

set of edges joined end to end

(a)  

2 graphs that have the same structure are:

(a)  

subdivisions create (a)   extra vertex and edge

what subgraphs subdivision disproves planarity? (a)   and K3,3

what subgraphs subdivision disproves planarity? K5 and (a)  

if a graph contains a subgraph of a SUBDIVISION of K5 or K3,3, it is (a)  

complete graphs with n vertices denoted by

(a)  

v + f = e + _

(a)  

v + f = _ + 2

(a)  

_ + f = e + 2

(a)