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Homework Help: +-2npi OR +-npi How do you know which one to attach?

  1. Jan 26, 2012 #1
    1. The problem statement, all variables and given/known data

    a. tan4x=1

    If tanTheta=1, then Theta=pi/4+-npi radians.

    4x=pi/4+-npi

    x=pi/16+-npi/4

    b. sin(x+2pi)+sin(x-2pi)=1/2

    sinxcos2pi+cosxsin2pi+sinxcos2pi-sin2picosx=1/2

    2sinxcos2pi=1/2

    sinxcos2pi=1/4

    sinx=1/4

    arcsin(1/4)=0.2526+-2npi



    2. Relevant equations
    3. The attempt at a solution

    So how do you know which one to attach +-npi or +-2npi? I have a slight suspicion that it might be due to periods of trig functions, but I don't trust myself when it comes to math.

    Thanks.
     
  2. jcsd
  3. Jan 26, 2012 #2

    ehild

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    What is the period of the tangent function, and what is the period of the sine and the cosine functions?

    ehild
     
  4. Jan 26, 2012 #3
    The tangent function repeats itself every pi and sine cosine functions repeat every 2pi?
     
  5. Jan 26, 2012 #4

    ehild

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    Yes, correct.

    ehild
     
  6. Jan 26, 2012 #5
    Thank You, Ehild.
     
  7. Jan 26, 2012 #6

    ehild

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    You are welcome.

    ehild
     
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