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    (Original post by philo-jitsu)
    Its the silver 1 paper question 4 part b

    its binomial expansion but the second part is a bit odd

    https://5a302d29ff432793ce79475dd3db...%20Edexcel.pdf
    Thats confused me as well

    What did you get as your expansion because i cant seem to get the same x^3 coefficient as them
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    (Original post by SeemaG18)
    Thats confused me as well

    What did you get as your expansion because i cant seem to get the same x^3 coefficient as them
    Ive got it now,

    you cant use 8-9x=7100, which rearranges to get x=-788 because we are given limits at the start that say modx<9/8

    so thats why we have to take cubed root 1000 which = 10 out to get 8-9x=7.8 which rearranges to get an x that falls within the limits

    might not have explained well but someone just helped me with it on another forum
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    also usually when your coefficient is wrong its a simple maths error, just double check it should be quick to find
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    (Original post by philo-jitsu)
    Ive got it now,

    you cant use 8-9x=7100, which rearranges to get x=-788 because we are given limits at the start that say modx<9/8

    so thats why we have to take cubed root 1000 which = 10 out to get 8-9x=7.8 which rearranges to get an x that falls within the limits

    might not have explained well but someone just helped me with it on another forum
    Ohhh that makes so much more sense, i got the -788 but didnt get the right value when it was subbed in
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    Well, I actually managed to wake up fairly early this morning but I decided that I'd go to the library as I thought I'd get more work done there. So I travelled all the way to the library + when I got there I realised that I'd forgotten my Biology textbook. Like, I don't even know how that's possible bc you'd think it'd be the first thing I'd place in my bag but anyway, it obviously meant that I couldn't do any work which was ridiculously annoying bc I went all that way for absolutely nothing. >.>>>

    Anywayyyy, I had to go out again when I got home + I just got back home again + I'm going to unpack my body then I'll start bio notes. Need to work really hard for the rest of today to make up for it.

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    Finally done the D1 paper, got 67/75, dropped marks because I couldn't be bothered to do that great big Gantt chart at the end, otherwise would've got 71/75

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    I finished my biology flashcards yesterday so now I'm condensing my chemistry notes. I woke up so late today though urgh

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    Going to do the June 2011 paper now

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    68/75 on core 4 silver 2, made stupid error and also didn't know area of a parallelogram....

    dont know if ive got another paper in me.....may watch a film then come back, done 4.5 hours so far need a break i reckon
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    Finished my second chemistry paper and I was also doing a few NMR questions from different past papers, and I can do them quite quickly now I'll practice some more NMR, then do another past paper
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    Done and marked June 2011 paper, got 65/75 which was an A so I'm ok with that.

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    (Original post by Kamara7)
    Finished my second chemistry paper and I was also doing a few NMR questions from different past papers, and I can do them quite quickly now I'll practice some more NMR, then do another past paper
    tips for nmr? i never get the final structure right?! also where else can i find practise qs


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    Gonna do Jan 2011 noe

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    Well, I'm still making my Biology notes; almost done with topic 6 then I'll move onto succession.
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    This is the week when pretty much all my exams are happening, yet I have so little motivation to work hard. I've spent most of today rewatching got.
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    (Original post by ranz)
    tips for nmr? i never get the final structure right?! also where else can i find practise qs


    Posted from TSR Mobile
    Have a structured attempt at the question. I always structure the big NMR questions like this:

    The singlet/doublet/whatever at 2.7ppm is caused by a H (or a number of Hs if they give you the ratio of Hs for the peaks) in a R-CH (or something else, literally copying the structure the data sheet gives) environment adjacent to however many Hs (remember the n + 1 rule), then I draw what this peak tells me. If you analyse all the peaks like this, you should get a bunch of marks
    (I always say how many peaks there are in total, and then that's how many H environments there are)

    So for example: the triplet at 2.9 ppm is caused by 2 Hs in a C6H5-CH environment adjacent to 2 Hs:
    C6H5-CH2-CH2-

    Remember to use other clues in the Q as well, if it's an ester, then there should be a peak for HC-CO- for the H next to the C=O carbon.

    For piecing the molecule together, look for things that overlap. Like if you found that two peaks suggest the structures CH3-CH2- and CH3-CH2-O-, then you can guess that the CH3-CH2- overlap.

    More NMR Qs: https://www.tes.com/teaching-resourc...stions-6259747
    (Make a TES account).

    If you have any more questions, I'll try to answer them
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    Ooooohhhhh noooooo. Done with anarchism (erm, for now... :erm:) but the realisation that I have about 5 more ideologies (minimum) to cover is dawning upon me - why is this so hard. :cry2:
    Now moving on to liberalism again :sigh: - think I'll have to gamble a bit and skip reading revision notes and just cover every single essay that has come up. :work:
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    yay, I've just completed all my Bio 4 notes.

    :party:


    Think I'm going to take a break now, then I'll start making my Chem 4 notes bc that's on Tuesday + I think biology memorisation/preparation can wait a little.
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    Hey CONGRATS! Have you learnt any of unit 4 and 5 yet? Also may I ask what grades you're hoping for?
    (Original post by Anon_98)
    yay, I've just completed all my Bio 4 notes.

    :party:


    Think I'm going to take a break now, then I'll start making my Chem 4 notes bc that's on Tuesday + I think biology memorisation/preparation can wait a little.
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    going to write essay plans for NML and virtue ethics for philosophy exam on wednesday
 
 
 
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