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  1. Sep 19, 2010 #1
    1. The problem statement, all variables and given/known data
    http://gyazo.com/f4c02f2a57b24a39dfee575837e0a807.png


    2. Relevant equations
    Ax = A cos (?)
    Ay = A sin(?)


    3. The attempt at a solution
    I tried putting the magnitude of x cos (?) but honestly have no idea what to do. Thanks
     
  2. jcsd
  3. Sep 19, 2010 #2

    cronxeh

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    Gold Member

    Angle between B and x-axis: arccos(6/sqrt(61))
    Angle between B and y-axis: arccos(4/sqrt(61))
    Angle between B and z-axis: arccos(3/sqrt(61))
     
  4. Sep 19, 2010 #3
    Where did you get those numberts?
     
  5. Sep 19, 2010 #4

    cronxeh

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    Gold Member

    B = 6i + 4j + 3z

    Bx = B * cos(angle between x-axis and vector B) ->>cos(angle) = Bx / B ->> angle = arccos(Bx/B)

    By = B * cos(angle between y-axis and vector B) ->>cos(angle) = By / B ->> angle = arccos(By/B)

    Bz = B * cos(angle between z-axis and vector B) ->>cos(angle) = Bz / B ->> angle = arccos(Bz/B)

    B = sqrt(6^2 + 4^2 + 3^2) = sqrt(61)

    angle between x-axis and B = arccos(6/sqrt(61))
    angle between y-axis and B = arccos(4/sqrt(61))
    angle between z-axis and B = arccos(3/sqrt(61))
     
  6. Sep 19, 2010 #5
    This is wrong. ?
     
  7. Sep 19, 2010 #6

    cronxeh

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    Gold Member

    You didnt convert radians to degrees did you, no you didn't

    You done didn't, did ya..

    x-axis and B = 39.8055 degrees
    y-axis and B = 59.1930 degrees
    z-axis and B = 67.4114 degrees
     
  8. Sep 19, 2010 #7
    =) Thank you.
     
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