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Homework Help: Cross product by epsilon ijk method

  1. Mar 6, 2010 #1
    1. The problem statement, all variables and given/known data
    I need to calculate Ax(BxC) -A, B, C are vectors, apart from bac-cab rule, I need to get it by epsilon ijk -Following I will note it by e(ijk).

    2. Relevant equations
    I expect answerer to know kronecker delta equation and vector multiplications.


    3. The attempt at a solution

    e(ijk)*A(i)*(B*C)(j)
    = e(ijk)*A(i)

    (BxC)(j) = e(mjn)B(n)C(m)

    After that part I'm stuck. As you can see below, I rotate the ijk's and mjn's to match j's at the end, but I fail.

    e(ijk)*A(k)*e(mjn)*B(n)*C(m)

    Can you help me after that?
    Lettters in parantheses (i, j, k, m, n) are supposed to indicate the indices.
     
  2. jcsd
  3. Mar 6, 2010 #2

    vela

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  4. Mar 7, 2010 #3
    I know Wikipedia, but if someone would bother to actually solve the question, I will be glad.
     
  5. Mar 7, 2010 #4

    cristo

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    I'm afraid that's not how things work around here-- if you come here asking a question you should be prepared to put in the work to find the solution. Homework helpers are here to help guide you to a solution.

    So, can you apply some of the relations on the page vela showed you to your problem?
     
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