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Homework Help: Discrete Math Proof

  1. Oct 18, 2012 #1
    1. The problem statement, all variables and given/known data
    I attached the problem as a file.

    2. Relevant equations

    3. The attempt at a solution
    I get stuck on how to properly represent the summation. How does k find it's way as one of the sub-scripts?

    Attached Files:

    Last edited: Oct 18, 2012
  2. jcsd
  3. Oct 18, 2012 #2


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    Your post makes no sense and there is no attachment.
  4. Oct 18, 2012 #3
    I am so sorry, I'll fix that.
  5. Oct 18, 2012 #4


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    Okay, you have BTAT. Now, what is (AB)T?
  6. Oct 19, 2012 #5

    [itex]AB = \sum_k a_{ki}b_{jk}[/itex]

    [itex](AB)^t = \sum_k a_{ki} b_{jk} = \sum_k b_{jk} a_{ki} = B^tA^t[/itex]

    Does that look correct?
    Last edited: Oct 19, 2012
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