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Homework Help: Given one cross product, find another cross product

  1. Sep 16, 2012 #1
    1. The problem statement, all variables and given/known data
    Calculate the cross product assuming that u X w = <-7,1,8>
    Find (-3u + 4w) X w = ?

    2. Relevant equations
    I'm not sure. I know you have to relate the cross product to something inorder to find what u and w are, but don't know what equations to use.

    3. The attempt at a solution
    Don't know where to start
  2. jcsd
  3. Sep 16, 2012 #2
    I think it is best if you use these 3 characteristics.
    1. u x w = u w sin(theta)
    2. λu x w = λ (u x w)
    3. (u + v) x w= u x w + v x w
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