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Math Help - Trigonometric equation

  1. #1
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    Trigonometric equation

    Solve sin(3θ) - sin(2θ) = sin(6θ)sin(θ) for θ is less than 180 but greater than 0

    I've got as far as:

    2cos(2θ)(sin(θ) - sin(4θ)) = 0

    And I'm now stuck.

    Any help would be great
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  2. #2
    MHF Contributor
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    Re: Trigonometric equation

    Hey kinhew93.

    If your new expression is correct then cos(2x) = 0 and sin(x) = sin(4x). The cos term is easy and the sin term is also good when sin(2x) = 2sin(x)cos(x) which means you will get sin(4x) = 2*2*sin(x)*cos(x)*cos(2x) = sin(x) which means 4cos(x)*cos(2x) = 1 or cos(x)*cos(2x) = 1/4 which can be further reduced.
    Thanks from kinhew93
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