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    Write down the greatest value of
    1/x^2+4x+14
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    Do you know how to find stationary points?
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    (Original post by imaan567)
    Write down the greatest value of
    1/x^2+4x+14
    \frac{1}{a} is greatest when a is minimised as much as possible.
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    (Original post by imaan567)
    Write down the greatest value of
    1/x^2+4x+14
    Firstly your notation is ambiguous. I'm sure you meant to put a bracket around the last three terms.

    RDKGames has told you how to proceed. You need to find the minimum of the quadratic. The easiest way to do that is to complete the square.
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    1/10
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    (Original post by Kira Yagami)
    1/10
    Well that's not a very useful response.
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    (Original post by RDKGames)
    Well that's not a very useful response.
    I'd score his contribution lower than that.
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    (Original post by imaan567)
    Write down the greatest value of
    1/(x^2+4x+14)


    The denominator is x^(2) + 4x + 14.

    If you find the first derivative and set this = to zero, you get a value for x that results in the minimum value for f(x) and therefore the maximum value for the fraction.
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    (Original post by BrasenoseAdm)
    The denominator is x^(2) + 4x + 14.

    If you find the first derivative and set this = to zero, you get a value for x that results in the minimum value for f(x) and therefore the maximum value for the fraction.
    This is crying out to be done by completing the square. And strictly, if you're going to use calculus, you ought to show that it really is a minimum, so you'll need to look at f'' or whatever.
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    (Original post by RDKGames)
    Well that's not a very useful response.
    He said "write down". This suggests that he only wants the answer right?
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    (Original post by Kira Yagami)
    He said "write down". This suggests that he only wants the answer right?
    Rather than seek an argument, could you read the Forum Rules pinned to the top of the Maths Forum? Full solutions are not permitted here, we are supposed to nudge students towards finding the answer for themselves.
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    (Original post by Mr M)
    Rather than seek an argument, could you read the Forum Rules pinned to the top of the Maths Forum? Full solutions are not permitted here, we are supposed to nudge students towards finding the answer for themselves.
    I honestly thought he just wanted the answer. Maybe he just wanted to check it because he didn't have a mark scheme?

    I'm not even sure 1/10 is correct.
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    (Original post by Kira Yagami)
    I honestly thought he just wanted the answer. Maybe he just wanted to check it because he didn't have a mark scheme?

    I'm not even sure 1/10 is correct.
    No harm done. It is correct by the way.
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    (Original post by Mr M)
    No harm done. It is correct by the way.
    Thanks for the service you have provided on here. I'm quite sure I remember a Mr M who posted solutions to GCSE EDEXCEL MATHS exams in 2013 or so.
 
 
 
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