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Factorial Question

  1. Nov 30, 2006 #1

    I have a question about factorials that I'm hoping someone can help me with.

    I know that the factorial n! means the product of the integers from 1 to n, for example if I have 4! then this is equal to 4 x 3 x 2 x 1 = 24, but I have an equation which contains the term:


    I am not sure how to interpret this...for instance, if we assume that k=4 and n=8, does this give:

    = 4 x 7!
    = 4 x 5,040
    = 20,160

    Or does it give:

    =4 x 7!
    =3.0489 x 10^29

    I'm guessing it's the first one but am not sure...can someone confirm or provide the correct answer please?

    Many Thanks
  2. jcsd
  3. Nov 30, 2006 #2


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    Note that the notations:
    (k(n-1))!, k((n-1)!) CANNOT be misunderstood.

    The convention used, in order to save parentheses is:

    Note that this convention is akin to the one used with expressions involving a power:
    rather than [itex](A*B)^{n}[/tex]
    Last edited: Nov 30, 2006
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