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Homework Help: Inverse trig value

  1. Aug 29, 2014 #1
    1. The problem statement, all variables and given/known data

    Fin the value of arccot(pi/4)

    2. Relevant equations

    unit circle

    3. The attempt at a solution

    I honestly can't believe that I'm stuck on this as this shouldn't stump me.

    My logic is that since its inverse cotangent then its related to inverse tangent and so the value that this reduces to will be found in quadrant 1 or 4 only.

    The value I get reading the unit circle is 1, but my calculator says 1.502 and wolframalpha says 0.905.

    Can anyone help explain this? Thanks.
  2. jcsd
  3. Aug 29, 2014 #2


    User Avatar
    Homework Helper

    If you get 1 it means that you took the tangent of pi/4.

    You need the arc cotangent of pi/4, that is arctan(0.7854).

    If the tangent/cotangent is positive the angle is either in the first quadrant, or ? (not in the fourth).

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