I've drawn a diagram of a subgraph that is a subdivision of K3,3: http://img136.imageshack.us/img136/6504/k33fr0.png
The red vertices are the result of subdivisions, so they can be ignored. (there is also an edge from 7 to 8, but I forgot to draw it in)
What I want to know is, is this the answer to 2.a. or 2.b?
do u mean that u forgot to draw the edge from 6 to 8??
and also, where is your vertex 0? 0 is an element of right?
can anyone give me a hint on how to solve question 2a?
Oct 27th 2008, 07:39 PM
Originally Posted by TomP
2a's got to do with Euler's Formula and the fact that:
2q = r*(no. edges in each region) > r*(length of shortest cycle)
im a little confused i used Euler's formula and i got that the number of faces should be 9 which is clearly a lot less than it is in real life...is there any way i can work out the number of actual faces by looking at the graph? and also, where did u get the other formula from? and how do i calculate the number of edges in each region?