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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE General & Further Mathematics => Topic started by: Daenerys Targaryen on October 29, 2012, 04:31:27 pm

Title: [Graphs and Relations] Sliding technique
Post by: Daenerys Targaryen on October 29, 2012, 04:31:27 pm
So I'm going through some exam solutions and I see something called the 'sliding line technique', I've never heard nor learnt this before, and yet it seems to be an easier way of getting the max/min objective figure.

Anyone care to explain how to do it?

Thanks.
Title: Re: [Graphs and Relations] Sliding technique
Post by: Stick on October 29, 2012, 06:20:46 pm
Case I: Z=ax+by, Z=-ax+by
1. Let Z equal any number (a common multiple of a and b is ideal).
2. Draw the objective function onto the graph.
3. Position your ruler so it is parallel with the line and slide it from the bottom of the graph to the top of the graph. The first point crossed is the minimum and the last point crossed is the maximum.

Case II: Z=ax-by, Z=-ax-by
1. Let Z equal any number (a common multiple of a and b is ideal).
2. Draw the objective function onto the graph.
3. Position your ruler so it is parallel with the line and slide it from the top of the graph to the bottom of the graph. The first point crossed is the minimum and the last point crossed is the maximum.
Title: Re: [Graphs and Relations] Sliding technique
Post by: Daenerys Targaryen on October 29, 2012, 06:28:29 pm
Oh nice explanation. Clear and concise.
Does it work 100% with all of these kinda questions?
Title: Re: [Graphs and Relations] Sliding technique
Post by: Stick on October 29, 2012, 06:32:53 pm
Yes, but it might not work too well if the points are very close together. And, of course, this method does not give you the value of the maximum - it only locates it for you. :)
Title: Re: [Graphs and Relations] Sliding technique
Post by: Daenerys Targaryen on October 29, 2012, 06:36:54 pm
Aha yeah. Thanks dude.