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Math Help - I dunno what to do!!?? solve sine equation

  1. #1
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    I dunno what to do!!?? solve sine equation

    solve for exact solution over interval [0*,360*)

    cot(x) + 2csc(x) = 3
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  2. #2
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    Quote Originally Posted by xxpl510xx View Post
    solve for exact solution over interval [0*,360*)

    cot(x) + 2csc(x) = 3
    Multiplby by \sin x,
    \cot x\sin x+2\csc x\sin x=3\sin x
    Thus,
    \cos x+2=3\sin x
    Square both sides,
    (\cos x+2)^2=9\sin^2x
    \cos^2 x+4\cos x+4=9\sin^2 x
    Thus,
    \cos^2 x+4\cos x+4=9(1-\cos^2x)
    Thus,
    \cos^2 x+4\cos x+4=9-9\cos^2 x
    Thus,
    10\cos^2x+4\cos x-5=0
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  3. #3
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    Im was close
    dumb mistakes
    I just didnt square the 3sin9(x) properly

    thanks a bunch perfecthacker
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