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    (Original post by physicsmaths)
    Dd they not do aswell as the June 13 event?


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    in 2013 all but one got 100% (but they were a stronger cohort)

    this lot have done good but not exceptional (with one exception) assuming the boundaries come roughly as I expect them
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    (Original post by yelllowribbon)
    urgh ffs im ****ting myself for this exam
    Same, i'm literally on the toilet seat
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    (Original post by Gilo98)
    Could do. Doubt they would give curve parametrically though. Thus, all you would need to do is

    



\pi\displaystyle\int^y_y x^2\ dy\
    Hope so, does say this in the spec though... π ⌠ y2 dx is required, but not π⌠x2 dy . Students should be able ⌡ to find a volume of revolution,given parametric equations.
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    (Original post by Hudl)
    how is c4 constantly 75/75 for full ums....is the date normally later than our date for c4, I feel like with the way my exams a scheduled I cant revise effectively for c4 as I have biol5 and chem5 aswell day after day. Only done like 3 papers for c4 aswell and that was before easter


    EDIT:

    If you want to change the limits on an integral eg you have a 1 at the top and 2 at the bottom and you have a negative inside the integral can you bring this out removing it and change the limits?
    Yes when you swap the top and bottom limits it just creates a minus. If there's already a minus it cancels it out.
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    (Original post by rayquaza17)
    Yes only sensible way is the double angle formula.
    I can think of only one other way to integrate it, but that involves complex numbers which is FP2. Tbh I think the double angle formula is easier in this case.
    How would you use complex numbers (out of interest)?


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    (Original post by TeeEm)
    in 2013 all but one got 100% (but they were a stronger cohort)

    this lot have done good but not exceptional (with one exception) assuming the boundaries come roughly as I expect them
    That is just awesome!


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    (Original post by kingaaran)
    That is just awesome!


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    ..
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    (Original post by kingaaran)
    How would you use complex numbers (out of interest)?


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    https://en.wikipedia.org/wiki/Integr...Simple_example
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    (Original post by Hudl)
    is the date normally later than our date for c4, I feel like with the way my exams a scheduled I cant revise effectively for c4 as I have biol5 and chem5 aswell day after day.
    I know how you feel. Last year's C4 was on the 18th, the day after unit 5 Chem and the day before unit 5 Physics. Could be worse, if you did all 3 sciences. I guess they annoyingly arrange it so that all the unit 4s are in 1 week, etc. Hang in there!
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    (Original post by JamieF95)
    Hope so, does say this in the spec though... π ⌠ y2 dx is required, but not π⌠x2 dy . Students should be able ⌡ to find a volume of revolution,given parametric equations.
    if it says
    



 \pi\displaystyle\int^y_y x^2\ dy\ \mathrm{is\ not\ required\ but} 



 \pi\displaystyle\int^x_x y^2\ dx\ \mathrm{is\ required\ then\ we\ will\ not\ be\ expected\ to\ find\ the\ volume\ of\ revolution\ about\ the\ y\ axis}





\mathrm{Hence\ the\ only\ parametric\ form\ you\ need\ to\ be\ comfortable\ with\ is...}



\pi\displaystyle\int^t_t y^2\frac{dx}{dt}\ dt
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    (Original post by TeeEm)
    in 2013 all but one got 100% (but they were a stronger cohort)

    this lot have done good but not exceptional (with one exception) assuming the boundaries come roughly as I expect them
    do you think this year was that hard? Personally found it quite reasonable - some weird questions but nothing too challenging although i suspect I made an error on one Q.

    (please don't discuss answers, I refrain from exam post-mortems; don't see the point in discussing answers tbh)
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    My teacher told us that when integrating 1/x , we should use the modulus lines but in the mark schemes, lt's simply ln(x). Which should I do?
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    https://5c59854d0ccd29d489c9e5e689a8...%20Edexcel.pdf

    how do you deal with sin3xcosx in 3b?
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    (Original post by Gilo98)
    Yes - wasn't as difficult as some of the IGYB beasts. Agreed - love 'show' questions in exams for the same reason, it seems they tend to ask these sorts of questions towards the end of the paper to somewhat soften the blow of the harder ones.

    No worries, look forward to it.
    this will hurt now

    I need some proof reading (very tired now)
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  1. File Type: pdf New Parametric volume hard.pdf (29.0 KB, 82 views)
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    (Original post by Leking9)
    My teacher told us that when integrating 1/x , we should use the modulus lines but in the mark schemes, lt's simply ln(x). Which should I do?
    Mathematically, ln|x|
    They always normally give cases of x>0 so |x|=x


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    (Original post by Gilo98)
    do you think this year was that hard? Personally found it quite reasonable - some weird questions but nothing too challenging although i suspect I made an error on one Q.

    (please don't discuss answers, I refrain from exam post-mortems; don't see the point in discussing answers tbh)
    nowhere as hard as June 2013
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    (Original post by physicsmaths)
    Mathematically, ln|x|
    They always normally give cases of x>0 so |x|=x


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    So why does the mark scheme say lnx or ln(x) - I've always wondered this
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    (Original post by TeeEm)
    nowhere as hard as June 2013

    but 100 ums still considerably less than 75?

    (Original post by TeeEm)
    this will hurt now

    I need some proof reading (very tired now)
    I'll try it tomorrow and be sure to let you know how I get on
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    (Original post by Gilo98)
    but 100 ums still considerably less than 75?


    I'll try it tomorrow and be sure to let you know how I get on
    around 70/75

    the parametric is not that hard (I am only joking)
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    Someone help me with an OCR C4 quesiton. The OCR thread is dead, like literally...

    Name:  C4 ....jpg
Views: 133
Size:  46.7 KB


    6ii and 7iii.

    For 6ii. If it was parallel to y-axis it would mean it would be =infinity.
    So the bottom of the fraction for part i is 0.

    2xy-3=0 Can someone explain how that shows there are no tangents parallel to the y-axis?

    Not sure how you do 7iii.

    Thanks
 
 
 
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