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Homework Help: A quick question on determinants!

  1. Mar 25, 2009 #1
    1. The problem statement, all variables and given/known data
    If the determinant of a 3 x 3 matrix A is det(A) = 10, and the matrix B is obtained by multiplying the third row by 8, then det(B) = ___?

    If the determinant of a 5 x 5 matrix A is det(A) = 9, and the matrix C is obtained from A by swapping the second and fourth rows, then det(C) =___?

    2. Relevant equations

    Ok, so do I use a generic matrix, or what? SO confused....

    3. The attempt at a solution
  2. jcsd
  3. Mar 25, 2009 #2


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    Science Advisor
    Homework Helper

    Hi LaraCroft! :smile:

    Useful tip: write out a few matrices (easy ones, with lots of zeros :wink:), and see what happens …

    then you can set about proving why :smile:
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