ATAR Notes: Forum
VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE General & Further Mathematics => Topic started by: pas0005 on November 04, 2012, 05:44:34 pm
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Hey all,
To put it plainly I fervently detest cuts. How on earth do you figure them out? I don't understand why some paths are considered as a 0. Please help!!
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Hey all,
To put it plainly I fervently detest cuts. How on earth do you figure them out? I don't understand why some paths are considered as a 0. Please help!!
Your question seems to refer to Networks rather than Graphs and Relations.
Shade in all the vertices and edges on the left hand side of any cut that you are looking at. If the source is in the shaded part of the graph, then every edge that is directed from the unshaded side into the shaded side is flowing from the sink to the source and counts as zero. This assumes that the source and the sink are not both on the same side of the cut under consideration.
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Woops! My apologies, I did mean networks. My sleep deprived brain fails to register such details.
Thank you though, I think I actually understand what to do now.
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(http://s8.postimage.org/rvlkiy7l1/awdawdaw.jpg)
That's what I did in the exam on Friday. Shaded the side where the source is coming from, and from there any arrows entering the region are labelled as zero :)
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You appear to have got it.
You should be able to see that Line 1 in the diagram has both the source and the sink on the same (right-hand) side of the line and so this is not considered to be a "cut" at all as it does not separate the source from the sink.
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In the exam I just looked at this question vacantly. Me and Maths aren't the best of friends.