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Homework Help: Finding x and y components from an angleplease help!

  1. Aug 23, 2010 #1
    1. The problem statement, all variables and given/known data
    A unit vector lies in the xy plane, at an angle of 131 degrees from the +x axis, with a positive y component. What is the unit vector?


    2. Relevant equations

    cos[STRIKE]O[/STRIKE]=adj/hyp


    3. The attempt at a solution

    cos131*=adj/hyp
    I know that the z component is obviously 0 (xy plane). The x component is negative in order for the angle to be 131*.

    So...
    -.656=adj/hyp

    And...
    ((sqrt)x^2+y^2)=1 since it's a unit vector.


    Basically, I don't know where to go from here. I know the magnitude is 1, and I know what the angle is, but I don't know how to find out the x and y component values. Any help is greatly appreciated.
     
  2. jcsd
  3. Aug 23, 2010 #2
    Edit-
    I got it. Duh. The hypotenuse has to be 1. Then cos0=Ax, and it's all plugging in stuff from there.
     
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