Factorials At Work

What are factorials?                              Why would you use factorials          ?

The factorial of a number is the           Factorials are useful. They can show

product of all the whole numbers,       how many different ways there are to

except zero, that are less than or          order or arrange a set of things.

equal to that number.

 

N

N!

1

1

2

2

3

6

4

24

 

 

This shows the progression from 1 to 4 in the factorial world. As you can see the graph jumps from 1 to 24 in just a change of 4 numbers.

 

 

How would you solve a factorial division?

6!/4!=6*5*4*3*2*1         6*5= 30.

          ----------------    =
          4*3*2*1

Why is this? The 4! cancels out of the 6! and leaves the 5*6 part of the problem. We all know that 5*6= 30 and there is your answer.

 

My Links:

http://www.themathpage.com/aPreCalc/factorial.htm

http://www.newdream.net/~sage/old/numbers/fact.htm

http://mathworld.wolfram.com/Factorial.html

http://mathforum.org/library/drmath/sets/mid_factorials.html

http://www.google.com

http://www.gomath.com/algebra/factorial.php

http://regentsprep.org/Regents/math/factnot/Lfact.htm

 

 

To contact Mr. Young for more expert tutelage: dyoung@fayar.net or dyoung7@fprodigy.net

 

History of the Factorials:
Multiple scientists worked on this subject, but the principal inventors are J. Stirling in 1730 who gives the asymptotic formula after some work in collaboration with De Moivre, then Euler in 1751 and finally C. Kramp and Arbogast who introduces between 1808 and 1816 the actual notation: n!. Of course other scientists such as Taylor also worked a lot with this notation.

 

My name is Kevin Walsh, I am in 1st period Pre-calculus with DAYoung and I made this webpage because I have an extreme interest in factorials. Also, there is the other reason, I made this webpage because it is a requirement on DA’s awesome final portfolio!