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Math Help - absolute max and mins

  1. #1
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    absolute max and mins

    Find the absolute max and mins of f on the given interval.
    f(x)=2cos(x) + sin(2x), [0, \frac{pi}{2}]

    f'(x)=-2sin(x) + 2cos(2x)=0
    cos(2x)=sin(x)<br />
    I got stuck after this.
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  2. #2
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    Remember that cos (2x) = 1 - 2 (sin x)^2
    So use that on the LHS, then you'll have a quadratic to solve fo sin x.
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