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Homework Help: Gaussian Elimation with Partial Pivoting Algorithm by hand

  1. Feb 16, 2010 #1
    1. The problem statement, all variables and given/known data

    The Gaussian Elimination with Partial Pivoting algorithm when applied to the following matrix

    A[-3 0 4; 5 2 -6; 0 0 1]

    Will construct matrices P, L, and U

    1- What are the defining properties of the matrices P, L and U?

    2- What relation do P, L, U and A always satisfy?

    3- Given that

    L=[1 0 0, -3/5 1 0; 0 0 1]

    What are P and U?


    2. Relevant equations

    PA=LU

    3. The attempt at a solution

    How do I do this by hand?
    There is rref command on the Ti89, the is lu(A), A\b, inv(A)*b on matlab......

    Anyways I know how to get the answer by doing this http://www.youtube.com/watch?v=euIXYdyjlqo" but I don't know how to construct the matrices that he wants, this is not homework is a review for a test on Monday.

    I know
    P= is the permutation matrix= it switches rows
    L= lower triangular matrix
    U= upper triangular matrix.

    So I need, to this by hand. Can someone send link or help me on how to do this step by step?

    Thanks
     
    Last edited by a moderator: Apr 24, 2017
  2. jcsd
  3. Feb 20, 2010 #2
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