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Homework Help: Vector product

  1. Feb 25, 2009 #1
    1. The problem statement, all variables and given/known data

    Two vectors are given by A = -2 i + 5 j and B = 2 i + 3 j
    Also find the angle between them

    2. Relevant equations

    Not really sure but from my book i get A x B = -B x A

    3. The attempt at a solution

    the answer is -16, but I'm confused I thought that it should look like -6 + 10 but why is it minus ten?

    How would I use this to find the angle?
     
  2. jcsd
  3. Feb 25, 2009 #2
    Do you know how to set up a determinant for vector product? From the determinant you can easilly calculate the product vector. Remember the result of a vector product is always a vector.

    When you know the vector product you can find the angle from

    (AxB)=|A||B|sin(A,B)

    Where A and B are the 2 vectors, (AxB) is the vector product and |A|/|B| are the lenghts of the vectors.
     
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