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    Show that the maximum value of lnx/x3 is 1/3 e-1

    I tried the quotient rule which gave me (x2 - lnx(3x2))/x6

    ​I don't know how to proceed from here can someone help
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    (Original post by bl64)
    Show that the maximum value of lnx/x3 is 1/3 e-1

    I tried the quotient rule which gave me (x2 - lnx(3x2))/x6

    ​I don't know how to proceed from here can someone help
    What do you usually do to find a maximum it minimum?
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    (Original post by TenOfThem)
    What do you usually do to find a maximum it minimum?
    make it = 0 and then differentiate again to work out what type of stationary point it is
    but i don't know what number makes it =0
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    (Original post by bl64)
    make it = 0 and then differentiate again to work out what type of stationary point it is
    but i don't know what number makes it =0
    Yes, make it 0

    For a fraction to equal 0 the numerator must equal 0

    I assume that the question stated that x was not zero
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    are mensuration formulae needed to differentiate given in the formulae booklet?:confused:
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    (Original post by Samira siddiqua)
    are mensuration formulae needed to differentiate given in the formulae booklet?:confused:
    The quotient rule is given
    Some rules for differentiating trig functions are given

    What were you looking for in particular
 
 
 
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