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Homework Help: Prove that if n ∈ ℕ where n > 1, then n! + 1 is odd.

  1. Feb 27, 2010 #1
    Prove that if n ∈ ℕ where n > 1, then n! + 1 is odd.
    n = k + 1, k = 1,...,∞
    Now substitute n!+1 = (k+1)! + 1 = ???

    I am not sure what to do next or if that is on the right path.
     
  2. jcsd
  3. Feb 27, 2010 #2
    If n > 1 then n! is an even number since it has 2 as one of its factors, so n! is even for n > 1. Conclude.
     
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