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Homework Help: Trigonometry interval problem

  1. Aug 15, 2010 #1
    1. The problem statement, all variables and given/known data

    Find all values of θ in the interval 0 ≤ θ ≤ 360 that satisfy the equation sin 2θ = sin θ

    2. Relevant equations

    sin2θ = 2sinAcosA

    3. The attempt at a solution

    I'm a little confused on how to start off knowing sin2θ is equivalent to 2sinAcosA, would you factor this?
  2. jcsd
  3. Aug 15, 2010 #2
    Re: Trigonometry

    sin2A = SinA
    2SinAcosA = SinA
    2SinAcosA - SinA = 0
    SinA (2CosA-1)= 0
    sinA = 0 2CosA-1=0
    A= 0,180,360 A= 60, 300

    i didn't check this, i just did this real quick, if i was wrong sorry, but i think i did it right
    Hope that helps
  4. Aug 15, 2010 #3
    Re: Trigonometry

    Thanks a lot for this :)
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