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Find the unit vector perpendicular to a and b

  1. May 20, 2007 #1
    1. The problem statement, all variables and given/known data
    there are two vectors a and b

    a=3i+2j+k
    b=2i+j+2k

    Find the unit vector perpendicular to a and b

    2. Relevant equations

    | A|^a=A
    3. The attempt at a solution

    I dont kno how to start
     
  2. jcsd
  3. May 20, 2007 #2
    go to mathworld.com and find what it means to be a perpendicular vector to
    2 other vectors.
     
  4. May 20, 2007 #3

    cristo

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    Well, calling the third vector c=(l,m,n), you should be able to find 3 equations. They will come from the facts that (i) a is perpendicular to c, (ii) b is perpendicular to c, and (iii) c is a unit vector.
     
  5. May 20, 2007 #4
    i tried to use the dot product and cross product but i still couldnt get the answer
     
  6. May 20, 2007 #5

    cristo

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    Well what did you try?
     
  7. May 20, 2007 #6

    malawi_glenn

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    Homework Helper


    Do you know the properties of vector (cross) product ?
    and this is precalculus math, not physics
     
  8. May 22, 2007 #7
    try using crossproduct,

    a x b = resultant(r)
    divide a x b by the magnitude of r,
    u will get ur unit vector
     
  9. Jun 26, 2007 #8
    ya axb..will give us vector whose unit vector is required
     
  10. Jun 26, 2007 #9
    yea..thnx....gt the answer long ago! thnx nywyz

    help much appreciated
     
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