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Math Help - Trig inequality

  1. #1
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    Trig inequality

    Hi, can you help me to solve this inequality?
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  2. #2
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    Dec 2008
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    by derivatives and logic

    2sin + 2cos +tan + cot + 1/sin + 1/cos=
    [2.sin^2.cos + 2.cos^2.sin + sin^2 + cos^2 +sin + cos]/(sin.cos)
    [sin(2sincos + 1) + cos(2sincos + 1) + 1 ]/(sincos)
    [(2sincos + 1)(sin + cos) +1 ]/(sincos)
    [(sin + cos)^3 +1]/(sincos)

    for sin+cos , min x= 45 or 225...(by derivative)
    for sin.cos , min x= 45 or 135 ...(by derivative)...and after the try, for each conditions, inaquality is true....

    so, answer is x=R / (90n) ....n=0,1,2,3.....




    sorry for my bad english
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