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Edexcel A2 C4 Mathematics June 2016 - Official Thread Watch

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    (Original post by anonwinner)
    Can anyone tell me where I went wrong in this question?

    https://i.imgur.com/QMYHjWd.jpg

    It's question 8b in this iygb paper http://www.madasmaths.com/archive/iy...apers/c4_l.pdf (mark scheme: http://www.madasmaths.com/archive/iy..._solutions.pdf)
    I think it has to do with the fact that you dropped the absolute value sign, without ensuring that the argument would stay positive.
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    (Original post by EricPiphany)
    I think it has to do with the fact that you dropped the absolute value sign, without ensuring that the argument would stay positive.
    I looked again at the mark scheme, and there is a part where I think the equation is rearranged incorrectly.


    Look at lines 6 and 7 of the solution for this question in the mark scheme
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    (Original post by anonwinner)
    I looked again at the mark scheme, and there is a part where I think the equation is rearranged incorrectly.


    Look at lines 6 and 7 of the solution for this question in the mark scheme
    'A' is an arbitrary constant and can be positive or negative. It's value wasn't set yet.
    You can verify in your solution BTW that the initial condition doesn't hold.
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    (Original post by anonwinner)
    I looked again at the mark scheme, and there is a part where I think the equation is rearranged incorrectly.


    Look at lines 6 and 7 of the solution for this question in the mark scheme
    In fact, there is a slight error, there should be a plus-minus sign on the fifth line, before the exponential.
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    (Original post by EricPiphany)
    In fact, there is a slight error, there should be a plus-minus sign on the fifth line, before the exponential.
    So should I have kept the modulus signs around 4 - 5h and then I would have got the correct answer?
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    (Original post by anonwinner)
    So should I have kept the modulus signs around 4 - 5h and then I would have got the correct answer?
    Just change to 5h - 4, to make it positive at h = 4, notice that it can't change sign without t going to infinity. Most probably simpler to do it as in solution.
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    (Original post by EricPiphany)
    Just change to 5h - 4, to make it positive at h = 4, notice that it can't change sign without t going to infinity. Most probably simpler to do it as in solution.
    At what stage can you just change it to 5h - 4?
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    (Original post by anonwinner)
    At what stage can you just change it to 5h - 4?
    I would say as soon as you notice that 4 - 5(4) is negative. But what do I know
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    (Original post by EricPiphany)
    I would say as soon as you notice that 4 - 5(4) is negative. But what do I know
    Ok thanks for the help
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    (Original post by SeanFM)
    What specific problems are you having?
    Mainly just all of the integration stuff, most of the time I have no idea which method to use and when I revise one method I forget how to do the others..
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    (Original post by kiasne)
    Mainly just all of the integration stuff, most of the time I have no idea which method to use and when I revise one method I forget how to do the others..
    Maybe it's worth practicing the mixed exercise so you get tested on different ones?

    If all else fails, try using every method until you find the right one (try as in, you probably won't get very far or have no idea to apply one method so move onto another one)

    But practice is the key.
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    (Original post by SeanFM)
    But practice is the key.
    are iygb similar to solomons?
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    (Original post by tazza ma razza)
    are iygb similar to solomons?
    I'm not sure, I'm too old to have used them properly. Worth a look though
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    (Original post by SeanFM)
    I'm not sure, I'm too old to have used them properly. Worth a look though
    ahaha kk no worries, thanks
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    Incidentally I am resitting some maths + further maths papers and was wondering, if i was to get a lower mark this year than I got last year in a paper, which mark would be noted - the higher 2015 mark or my most recent lower 2016 mark?
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    (Original post by tazza ma razza)
    Incidentally I am resitting some maths + further maths papers and was wondering, if i was to get a lower mark this year than I got last year in a paper, which mark would be noted - the higher 2015 mark or my most recent lower 2016 mark?
    Highest mark out of the fdifferent sittings. But if you remark a paper and it drops the lowest mark goes.



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    (Original post by physicsmaths)
    Highest mark out of the fdifferent sittings. But if you remark a paper and it drops the lowest mark goes.



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    ah right ok - an example to double check, S3 i got 56 in 2015 if i was to get 90+ this year, 90+ would be the UMS that gets put forward?
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    (Original post by tazza ma razza)
    are iygb similar to solomons?
    Sort of, I've done one for C3 so far

    But IYGB can get ridiculously hard if you go for the papers at the further end of the alphabet
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    (Original post by tazza ma razza)
    ah right ok - an example to double check, S3 i got 56 in 2015 if i was to get 90+ this year, 90+ would be the UMS that gets put forward?
    Yep, but f you got 50 the 56 would go forward


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    (Original post by tazza ma razza)
    are iygb similar to solomons?
    Solomons are much closer to the real exam format, IYGB are harder and require a bit more thinking. Tbh i would start with the real papers where 100 ums isn't full (as they tend to be the harder ones) and if you still want more papers then look at solomons or IYGB
 
 
 
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