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Homework Help: Vector Product

  1. Jul 16, 2008 #1
    1. The problem statement, all variables and given/known data
    Can A X B = B? If so, find A, and illustrate with a picture
    B. If A=Axi+Ayj, find B such that A X B = Ayi-Axj

    2. Relevant equations
    I know A X B= ABsin[tex]\theta[/tex]

    3. The attempt at a solution
  2. jcsd
  3. Jul 16, 2008 #2
    You have missed the important part:

    3. The attempt at a solution

    Show some work, we won't simply give you the answers here!

    I will give you one hint though. The expression you gave (AxB = ABsin..) is technically not correct.
    The correct expression is:
    [tex]\left| \vec{A} \times \vec{B} \right| = \left| \vec{A} \right| \left| \vec{B} \right| \sin \theta[/tex]

    In other words, it only gives you the lenght of the vector. Don't forget what a vector is!
  4. Jul 16, 2008 #3
    Well i just need to know how to begin. I know If A is only in the x,y plane and B is only in the x,y plane then theres no way thats possible. However i don't know how to determine it with 3 different axis.
  5. Jul 16, 2008 #4

    D H

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    Staff Emeritus
    Science Advisor

    Student1, a vector is something with a magnitude and a direction.
  6. Jul 16, 2008 #5
    If you have:
    [tex]\vec{A} \times \vec{B} = \vec{C}[/tex],
    what do you know about the vector C in relation to A and B?
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