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Math Help - My simple trig is rusty..

  1. #1
    ixo
    ixo is offline
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    My simple trig is rusty..

    I'm solving for a derivative, which is no prob, but I don't remember all the trig rules. So leaving out the calculus the equation boils down to:
    f\prime(x)=\cos(\frac{\pi}{4})-(\frac{\pi}{4})\sin(\frac{\pi}{4})

    Which i can just plug in to my calculator and get a numerical answer but they want it factored into

    f\prime(x)=\frac{\sqrt{2}}{8}(4-\pi)

    Would someone mind showing me the steps again? I need to review my trig
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  2. #2
    MHF Contributor
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    Hi

    \cos \left(\frac{\pi}{4}\right) = \sin \left(\frac{\pi}{4}\right) = \frac{\sqrt{2}}{2}
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  3. #3
    ixo
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    trig common angles.. lol thx i was trying to open them up.
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