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Homework Help: Determinant of 4x4 matrix

  1. Feb 2, 2012 #1
    1. The problem statement, all variables and given/known data

    I was using the method shown in the following video;


    to find the determinant for the following 4x4 matrix

    1 -2 3 -4
    5 6 -7 8
    -9 -10 11 -12
    -13 14 -15 16



    3. The attempt at a solution

    I was therefore expanding this out by using the first three columns set to the right of this matrix.

    Is this the correct thing to do if using this method?

    I get an answer of -3264

    Though when I use this online determinant calculator
    http://www.bluebit.gr/matrix-calculator/
    it provides an answer of 0
     
    Last edited by a moderator: Sep 25, 2014
  2. jcsd
  3. Feb 2, 2012 #2
    Apparently this method simply doesn't work for a 4x4 matrix.
    And I've been told the correct answer is zero.

    Just that our lecturer stated when finding the determinant using this method;

    So I thought by this he meant doing what I had done above.
     
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