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Homework Help: Vectors and finding components

  1. Sep 30, 2010 #1
    1. The problem statement, all variables and given/known data
    If the x component of a vector A, in the xy plane, is half as large as the magnitude of the vector, the tangent of the angle between the vector and the x axis is:
    A rad 3
    B 1/2
    C (rad3) / 2
    D 3/2
    E 3

    2. Relevant equations

    3. The attempt at a solution
    I first drew a right triangle and realized that the description fit a 30 - 60 - 90 triangle. Is it wrong to assume that the vector and its components make a right triangle?

    So I assumed that the magitude of the vector was 2x, the x component x, and the y component (rad 3) x. The tangent of the angle between the angle and x axis I would then be (rad3)x / x = rad3.
    Is this correct? According to my answer sheet, the answer is D (3/2). I dont think the solution sheet is correct
     
  2. jcsd
  3. Sep 30, 2010 #2
    Y and X axis make a right angle in any reasonable coordinate system. So vector, x and y-axis will make a right triangle.
    If rad means square root, then [tex]\sqrt{3}[/tex] is the correct answer.
     
  4. Oct 1, 2010 #3
    Thanks! I think the answer sheet was wrong. And by rad 3 I did mean square root 3.
     
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