Monday, April 9, 2007

Permutations and such...

When Mr. Max first suggested us doing all of this research ourselves and trying out this whole 'students teaching students' thing i was quite skeptical to start with. I think that a teachers job is to teach and that's what they should do. But after talking with Mr. Max and reading what my fellow students have put on the blog, i am beginning to warm up to this idea. :)

anyways back to math....

Now i am sure this is going to be somewhat similar to what others have posted so please bare with me as i will try and find some new stuff on permutations!

A Permutation is the rearrangement of objects or symbols into distinguishable sequences. Each unique ordering is called a permutation.
as defined by the most helpful Wikipedia.

One person who played a major role in developing permutations was am man by the name of Augustin Louis Cauchy. He wrote a number of papers on the subject and this all happened around the year 1844.

Now the main formula for permutations is
---------> nPr <--------- n=is the number of digits you have to choose from
r=is the number of digits being used at a time (what you want)

....and if all of that mumbo jumbo didn't make sense to you, then here is an example which will hopefully help you out!

Question: >>>In how many ways can 8 CD’s be arranged on a shelf?<<<

Answer: First you must plug the numbers into the formula.
It would then look like 8P8.
After that you just have to do the multiplication which is 8*7*6*5*4*3*2*1= 40320
So there are 40320 ways to arrange that 8 CD's on the shelf. Wow that is a lot!

I am hoping that this scribe has helped you all understand permutations better. I know it helped me.

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