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Homework Help: Simple factorials!

  1. Nov 12, 2004 #1
    I forgot most things about factorials but now I have to use them again to simplify expressions while doing convergence tests... What I know is:

    [tex] (n +1) ! = (n +1) n! [/tex]

    [tex] (2n +1)! = (2n +1) 2n! ? [/tex]

    but I don't know how to deal with these:

    [tex] (n -1) ! = ?[/tex]

    [tex] (2n-1) ! = ?[/tex]

    Thanks for any help.
     
    Last edited: Nov 12, 2004
  2. jcsd
  3. Nov 12, 2004 #2
    I know they're pretty easy but I don't have any algebra text/reference to look them up... :redface:
     
  4. Nov 12, 2004 #3
    At first (2n+1)!=(2n)!(2n+1)
    (n-1)!=n!/n
    (2n-1)!=(2n)!/2n
     
  5. Nov 12, 2004 #4
    Thank you, sir. :)
     
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