C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST

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  1. icedragon's Avatar
    • Peer Of The TSR Realm
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    (Original post by Implication)
    It could have been, but we have no reason to suppose that it was. At best, it is possible that our answer was okay - but either way it was unjustified. We were told that y=2 at x=pi/4, and have given an answer where y=+/-2 and x=pi/4.

    Take the equation of a circle though, even if we were given only one point there would still be another x point at y=2. Just because they didn't give it to us we can't assume it's not there.
  2. tiny hobbit's Avatar
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    (Original post by Phenylethylamine_)
    Hey - I found an almost identical question to q1 in this paper..

    I got values of A and C right but B wrong, I did the entire correct method e.g. sub x=1 but just an arithmetic error made me get the wrong value of B to -3/2

    So I'll lose one accuracy mark 3/4 for part (a)

    I integrated the partial fractions correctly then..

    In June 2009 mark scheme I saw that they award follow through marks as long as it's correctly integrated, but then for part b, subbing the values it just says M1/A1/A1? (But it doesn't say cao or cso, so do they still give you marks from your follow through answer from part b?)

    So what does that mean? do we not get any marks awarded for subbing of values?
    From the mark schemes:

    "All A marks are ‘correct answer only’ (cao.), unless shown, for example, as A1 ft to indicate that previous wrong working is to be followed through. "

    See the markscheme for C4 Jan 2011. In questions 3b and 4b the accuracy marks are ft from the previous parts. In later parts of those two questions however, the A marks are not ft.

    Effectively, ft marks are often given if it is easy to see what has been done with the incorrect values. If following through would involve doing calculations, A marks are generally cao, even if it doesn't say so. The default is cao.
  3. otrivine's Avatar
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    (Original post by tiny hobbit)
    From the mark schemes:

    "All A marks are ‘correct answer only’ (cao.), unless shown, for example, as A1 ft to indicate that previous wrong working is to be followed through. "

    See the markscheme for C4 Jan 2011. In questions 3b and 4b the accuracy marks are ft from the previous parts. In later parts of those two questions however, the A marks are not ft.

    Effectively, ft marks are often given if it is easy to see what has been done with the incorrect values. If following through would involve doing calculations, A marks are generally cao, even if it doesn't say so. The default is cao.
    for the first question i got A B C correct values and for the next part i did the correct method but in one part i integrated wrongly so will i lose only 1 or 2 marks

    and/ if you get the correct method but wrong final answer how many marks do u lose
  4. Phenylethylamine_'s Avatar
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    (Original post by tiny hobbit)
    From the mark schemes:

    "All A marks are ‘correct answer only’ (cao.), unless shown, for example, as A1 ft to indicate that previous wrong working is to be followed through. "

    See the markscheme for C4 Jan 2011. In questions 3b and 4b the accuracy marks are ft from the previous parts. In later parts of those two questions however, the A marks are not ft.

    Effectively, ft marks are often given if it is easy to see what has been done with the incorrect values. If following through would involve doing calculations, A marks are generally cao, even if it doesn't say so. The default is cao.
    Well I wasn't gonna come again in this thread but you just quoted me :rolleyes:
    Ahh okay I see, um, well we'll at least get the M1 right for subbing values? ugh so annoying this is! What one numerical error can do :/
  5. dd3v's Avatar
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    (Original post by und)
    Those points aren't on the line, though, are they? There is an infinite number of solutions to 18xy=54, so there are infinite pairs of x and y for which dy/dx=0, but only two of these pairs lie on the curve.
    I'm saying I subbed in y=54/18x and got the co-ordinates (72, 1/24) and (-72, -1/24)

    anyway, the question only asked for points when dy/dx=0
    Last edited by dd3v; 02-07-2012 at 11:49.
  6. Glacier's Avatar
    • Respected Member
    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    (Original post by smith50)
    How many marks would i loose in Q7 due to my calculator being in radians - but have the right answer in different mode.
    Are you talking about Edexcel? There was no trigonometry in Q7 of the Edexcel C4 paper.
  7. Extricated's Avatar
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
  8. jandroman767's Avatar
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    I know it's a bit late, but im a bit worried. I was looking at the official mark scheme and I got 2 big doubts

    First is, if my answer on 3)a was 2+(2/x)+(4/27x)+(40/729x), missing the 4/x, would I happen to loose 1 mark or 2 marks for the 2 final accuracy marks? The mark scheme states they want to see 2+4/x, but wouldn't that be a carried mistake on to the last accuracy mark for the whole question, and therefore only loosing 1?

    Second, the method marks awarded by edexcel on the substitution questions, for example 1bii) is given out just for attempting to substitute the values 2 and 1 for example, or only for getting the correct signs and values? I ended up getting a - sign in one of the numbers instead of a + sign because of a silly mistake , and i want to know if i only lost 1 mark or 2.

    Thanks guys and good luck!
    Last edited by jandroman767; 05-08-2012 at 15:06.
  9. MJ1993's Avatar
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    • Posts: 94
    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    (Original post by jandroman767)
    I know it's a bit late, but im a bit worried. I was looking at the official mark scheme and I got 2 big doubts

    First is, if my answer on 3)a was 2+(2/x)+(4/27x)+(40/729x), missing the 4/x, would I happen to loose 1 mark or 2 marks for the 2 final accuracy marks? The mark scheme states they want to see 2+4/x, but wouldn't that be a carried mistake on to the last accuracy mark for the whole question, and therefore only loosing 1?

    Second, the method marks awarded by edexcel on the substitution questions, for example 1bii) is given out just for attempting to substitute the values 2 and 1 for example, or only for getting the correct signs and values? I ended up getting a - sign in one of the numbers instead of a + sign because of a silly mistake , and i want to know if i only lost 1 mark or 2.

    Thanks guys and good luck!
    How the hell do you remember what you put?
  10. James A's Avatar
    • You guessed it, I'm a big F1 fan :yep:
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    Gordon Bennett, you guys are still discussing this paper? get over it
  11. rafishakouri's Avatar
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    • Location: London
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    This is the only exam that i'm not nervous about results wise
  12. jukebox123's Avatar
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    (Original post by rafishakouri)
    This is the only exam that i'm not nervous about results wise
    Same here, I'm expecting at least 98 ums
  13. rafishakouri's Avatar
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    • Location: London
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    (Original post by jukebox123)
    Same here, I'm expecting at least 98 ums
    95+ for me hopefully I loved it!
  14. NutterFrutter's Avatar
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    I'm not that worried about this paper either.
  15. MJ1993's Avatar
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    • Posts: 94
    (Original post by NutterFrutter)
    I'm not that worried about this paper either.
    I wasn't worried until I saw this thread :/ I need 79 ums for my A :/


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  16. rock_climber86's Avatar
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    (Original post by Inactivity)
    Q6(c) y = 2\left(1\pm \sqrt{1-\frac{x^2}{3}} \right) seems legit?
    i'm trying to learn latex - looks hard :eek: how did you learn?
  17. Dark Lord of Mordor's Avatar
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    (Original post by rock_climber86)
    i'm trying to learn latex - looks hard :eek: how did you learn?
    I found this website very helpful http://www.codecogs.com/latex/eqneditor.php
  18. Glacier's Avatar
    • Respected Member
    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    (Original post by rock_climber86)
    i'm trying to learn latex - looks hard :eek: how did you learn?
    (Original post by SrijanParmeshwar)
    I found this website very helpful http://www.codecogs.com/latex/eqneditor.php
    This one is good as well: http://webdemo.visionobjects.com/equ...locale=default
  19. goofymark13's Avatar
    • Exalted Member
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    Does everyone agree with Arsey's grade boundaries? just asking cause they seem quite low :/
  20. NutterFrutter's Avatar
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    Re: C4 June 2012 - Post Exam Thread - Paper and Solutions in the FIRST POST
    (Original post by goofymark13)
    Does everyone agree with Arsey's grade boundaries? just asking cause they seem quite low :/
    They seemed slightly low to me as well. Anyway, not long left now. :ninja:
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