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    Hi everyone. I have my C2 exam tomorrow and I am very worried about one thing which involved modelling curves. When doing past papers I get the marks for drawing the graphs involving calculations of logarithms required for plotting them. However when I do the calculations to find out the constants involved especially the gradient , I do not get the answer in the range of what the mark scheme says. I am doing it as accurate as possible , even with the calculator I was keeping the values as they were but still it's not in the range. I am calculating the gradient as :change in y divided by change in x. Could anyone help me with this problem?




    Thank you
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    (Original post by beatrice15)
    Hi everyone. I have my C2 exam tomorrow and I am very worried about one thing which involved modelling curves. When doing past papers I get the marks for drawing the graphs involving calculations of logarithms required for plotting them. However when I do the calculations to find out the constants involved especially the gradient , I do not get the answer in the range of what the mark scheme says. I am doing it as accurate as possible , even with the calculator I was keeping the values as they were but still it's not in the range. I am calculating the gradient as :change in y divided by change in x. Could anyone help me with this problem?




    Thank you
    I think you need to give us a bit more info to go on

    Can you post an example question showing what calculations you've tried to do, and how/where it disagrees with the answer?
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    I've attached jan 2013 c2. As k I got 0.013. It is the last question on this paper. I did change in y divided by change in x.

    Thank you for your help

    (Original post by davros)
    I think you need to give us a bit more info to go on

    Can you post an example question showing what calculations you've tried to do, and how/where it disagrees with the answer?
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    It was k that got other calculation being not in the range and I just want to know how did they calculate this gradient
    (Original post by beatrice15)
    I've attached jan 2013 c2. As k I got 0.013. It is the last question on this paper. I did change in y divided by change in x.

    Thank you for your help
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    (Original post by beatrice15)
    It was k that got other calculation being not in the range and I just want to know how did they calculate this gradient
    It's hard to say for sure because obviously when you're plotting by eye on a graph there is bound to be some subjective judgement!

    I did a VERY rough estimate taking the 1st and last values for logp and for t, and got a value of 0.011506 which falls within their range, but apart from being very careful with your drawing I can't suggest anything else I'm afraid!

    Good luck with the exam
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    Thank you

    (Original post by davros)
    It's hard to say for sure because obviously when you're plotting by eye on a graph there is bound to be some subjective judgement!

    I did a VERY rough estimate taking the 1st and last values for logp and for t, and got a value of 0.011506 which falls within their range, but apart from being very careful with your drawing I can't suggest anything else I'm afraid!

    Good luck with the exam
 
 
 
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