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Math Help - Trig Function Simplification

  1. #1
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    Trig Function Simplification

    I'm trying to simplify the following, using the basic pythagorean identities or other basic trig:

    (cos^3 θ + sin^3 θ )/(sin θ + cos θ )


    Any help would be appreciated.
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  2. #2
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    (cos^3 θ + sin^3 θ )/(sin θ + cos θ )=
    =(cos θ + sin θ )*(cos^2 θ - sin θ cos θ + sin^2 θ) / (sin θ + cos θ ) =
    =cos^2 θ - sin θ cos θ + sin^2 θ = 1-sinθ cos θ =1-(1/2) sin2θ
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  3. #3
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    Nice! Thank you. So did you factor (cos θ + sin θ) out of the denominator?
    How did you go about doing that?
    Last edited by breadmaker; November 21st 2008 at 03:08 PM.
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  4. #4
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    a^3+b^3=(a+b)(a^2-ab+b^2)
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