1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Factorial Question

  1. Nov 30, 2006 #1
    Hi,

    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:

    k(n-1)!

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

    4(8-1)!
    = 4 x 7!
    = 4 x 5,040
    = 20,160

    Or does it give:

    4(8-1)!
    =4 x 7!
    =28!
    =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
    -Rob
     
  2. jcsd
  3. Nov 30, 2006 #2

    arildno

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

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

    The convention used, in order to save parentheses is:
    k(n-1)!=k((n-1)!).

    Note that this convention is akin to the one used with expressions involving a power:
    [tex]A*B^{n}=A*(B^{n})[/tex]
    rather than [itex](A*B)^{n}[/tex]
     
    Last edited: Nov 30, 2006
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Factorial Question
  1. Factorial Question (Replies: 2)

Loading...