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Prove by Induction that n! ≥ 2^(n-1) n ≥ 1

  1. Oct 4, 2013 #1
    prove by Induction that n! ≥ 2^(n-1) n ≥ 1
  2. jcsd
  3. Oct 4, 2013 #2


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    Okay, so show us what you have attempted.
  4. Oct 4, 2013 #3
    I managed to prove for n= 1 and is true
    for n=k k!≥ 2^ (k-1) and I assumed that n=k to be true

    then for n= k+1 its (k+1)! ≥ 2^[(k+1)-1]
    proof for n=(k+1)

    (k!)(k+1) ≥ _____?

    the problem is that how do we reach the proof for (k+1)
  5. Oct 4, 2013 #4


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    hi kudzie adore! welcome to pf! :smile:

    (try using the X2 button just above the Reply box :wink:)

    hint: if an equation is true, then multiplying both sides by the same factor will still be true :wink:
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