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    Hi there, we have just started the Trapezium Rule in class and I have tried to complete some extra questions at home for revision. However I have attempted one and got the wrong answer. If someone could show me the working out I would appreciate it. Thanks .

    'Use the Trapezium Rule with ordinates at x=1, x=2 and x=3 to estimate the value of ∫(top 3, bottom 1) √40-x^3 dx'
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    (Original post by garethhines)
    Hi there, we have just started the Trapezium Rule in class and I have tried to complete some extra questions at home for revision. However I have attempted one and got the wrong answer. If someone could show me the working out I would appreciate it. Thanks .

    'Use the Trapezium Rule with ordinates at x=1, x=2 and x=3 to estimate the value of ∫(top 3, bottom 1) √40-x^3 dx'
    What did you try?
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    (Original post by garethhines)
    Hi there, we have just started the Trapezium Rule in class and I have tried to complete some extra questions at home for revision. However I have attempted one and got the wrong answer. If someone could show me the working out I would appreciate it. Thanks .

    'Use the Trapezium Rule with ordinates at x=1, x=2 and x=3 to estimate the value of ∫(top 3, bottom 1) √40-x^3 dx'
    As above, mind showing us a picture of your working?
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    Just followed the steps I had done before. I'm normally great at making glaring errors though haha. Thanks again in advance.
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    (Original post by garethhines)
    Just followed the steps I had done before. I'm normally great at making glaring errors though haha. Thanks again in advance.
    You have the strip number wrong. If we are using 3 values, we have 2 strips (draw a graph and you will see that you have 2 trapeziums).
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    (Original post by 16Characters....)
    You have the strip number wrong. If we are using 3 values, we have 2 strips (draw a graph and you will see that you have 2 trapeziums).
    So what is it I am changing?
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    (Original post by garethhines)
    So what is it I am changing?
    Your h should be h = \frac{3-1}{2} = 1.
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    (Original post by Zacken)
    Your h should be h = \frac{3-1}{2} = 1.
    Oh okay, i get that now.

    That's great. Thank you both for your help!
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    (Original post by garethhines)
    So what is it I am changing?
    If you draw a sketch like this all the time, it is invaluable. h is the number of strips you have, and if you have three numbers, you get two strips, as below:

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    (Original post by Zacken)
    If you draw a sketch like this all the time, it is invaluable. h is the number of strips you have, and if you have three numbers, you get two strips, as below:


    Would the curve have to be exact or just a sketch?
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    (Original post by garethhines)
    Would the curve have to be exact or just a sketch?
    Just any random sketch, the curve I drew is some random piece of crap I drew up in paint, it doesn't look anything like the actual graph but it's just there to remind me of how many strips there are.
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    (Original post by Zacken)
    Just any random sketch, the curve I drew is some random piece of crap I drew up in paint, it doesn't look anything like the actual graph but it's just there to remind me of how many strips there are.
    Ah great, I'll keep that in mind for the future. Thanks again for your help.
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    (Original post by garethhines)
    Ah great, I'll keep that in mind for the future. Thanks again for your help.
    Cheers.
 
 
 
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