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Homework Help: Trig inequalities question

  1. Sep 29, 2009 #1
    1. The problem statement, all variables and given/known data
    Solve the following equations or inequalities in the interval [0, 2pi)

    tanx - 3cotx = 0

    2. Relevant equations

    3. The attempt at a solution

    tanx = 3cotx
    tanx = 3/tanx
    tan2x = 3
    tanx = +-sqrt3
    tanx = sqrt3 or tanx = -sqrt3

    tanx = sqrt3
    x = pi/3, 7pi/6

    tanx = -sqrt3
    x = 2pi/3, 11pi/6

    Is this right?
  2. jcsd
  3. Sep 30, 2009 #2


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    Homework Helper

    check your answers

    tan is periodic with a period of pi, your solutions for a given sign do not have period of pi
  4. Sep 30, 2009 #3
    Both your primary answers to each equation were correct.

    But why did you from answers with reference angles of pi/3 to that of pi/6 for your secondary answers?
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