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Which radian to use?

  1. Jul 5, 2008 #1
    I just have a simple question as to which radians to use in calculating phase constants in oscillations.
    For example in sin(theta) = 1/2, do I use the (pi)/6 or 5(pi)/6?

    The exact question has a diagram and is difficult to explain, but I just want a general explanation.

    Thank you!
  2. jcsd
  3. Jul 5, 2008 #2


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    It's a little hard to answer this without more information. If you're just trying to solve the equation,

    [tex]\sin \theta = 1/2 [/tex]

    then there are more than one solution.

    But you did say the problem deals with oscillations and phase constants. Can you use the information that:
    1) at pi/6, the oscillation's displacement is increasing
    2) whereas at 5 pi/6, the displacement is decreasing
    to somehow decide on one value or the other? The answer would depend on details of the problem you are trying to solve.
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