xam2morr

06-24-2006, 08:34 PM

I have a question that i am having a real hard time solving.

Question: Michelle wishes to create a rectangular dog enclosure along an existing wall. She has 18m of fencing.

Complete the following table of values for all possible rectangular enclosures with whole number dimensions.

I can do that, and it's as follows:

Finite

Length Width Area Differences

16 1 16

14 2 28 12

12 3 36 8

10 4 40 4

8 5 40 0

6 6 36 4

4 7 28 etc.

2 8 16

So I can pull from that (the finite differences) that the relationship is not linear. Then I had to graph it, which I had no problem with.

The part of this question i had real trouble with was:

Write an equation for area in terms of width (note: width only, no length)

I learned from a teacher that if you do finite differences for the first finite differences and they are constant, the equation will have a squared number in it, (the width) but I am so stumped from there. I was also told that you can make it like a y-mx+b eqution, if the line is linear, which it isn't.

Is there anything I can look at as far as relationships that are between width and area that work every time? Or do I have to just pretty much try and pick out a trend each time? I'm kinda in a pickle, and my exam is in less than two days. Hope you can help. Thank you!

Question: Michelle wishes to create a rectangular dog enclosure along an existing wall. She has 18m of fencing.

Complete the following table of values for all possible rectangular enclosures with whole number dimensions.

I can do that, and it's as follows:

Finite

Length Width Area Differences

16 1 16

14 2 28 12

12 3 36 8

10 4 40 4

8 5 40 0

6 6 36 4

4 7 28 etc.

2 8 16

So I can pull from that (the finite differences) that the relationship is not linear. Then I had to graph it, which I had no problem with.

The part of this question i had real trouble with was:

Write an equation for area in terms of width (note: width only, no length)

I learned from a teacher that if you do finite differences for the first finite differences and they are constant, the equation will have a squared number in it, (the width) but I am so stumped from there. I was also told that you can make it like a y-mx+b eqution, if the line is linear, which it isn't.

Is there anything I can look at as far as relationships that are between width and area that work every time? Or do I have to just pretty much try and pick out a trend each time? I'm kinda in a pickle, and my exam is in less than two days. Hope you can help. Thank you!