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Edexcel A2 C4 Mathematics June 2016 - Official Thread Watch

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    How's everyone revising for C4 (and C3) at this moment in time? Just past papers?

    I might do the all the Solomon papers for each one
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    (Original post by Serine Soul)
    It's on the C3 spec :dontknow:
    Ooo its come up on a paper i'm doing and my teachers never even mentioned it
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    SeanFM what's proving by counterexample?
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    (Original post by particlestudent)
    How's everyone revising for C4 (and C3) at this moment in time? Just past papers?

    I might do the all the Solomon papers for each one
    Past papers are the way to go !
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    (Original post by Don Pedro K.)
    Past papers are the way to go !
    I'm nervous for C4... C3 isn't too bad but because the M1 exam went well, it makes it slightly better
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    (Original post by Don Pedro K.)
    SeanFM what's proving by counterexample?
    Stupid person: 'i think every number is odd'
    you: 'but what about 2,4 and 6'
    Stupid person 'oh yeah'
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    (Original post by joodaa)
    Ooo its come up on a paper i'm doing and my teachers never even mentioned it
    (Original post by Don Pedro K.)
    SeanFM what's proving by counterexample?
    Best person to ask is someone doing it in a paper never bothered learning it in C3 (didn't know it existed, or if I did I wouldn't know it by name) and don't really remember it from first year uni stuff :hide:

    I guess contradicting a statement works.
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    (Original post by particlestudent)
    I'm nervous for C4... C3 isn't too bad but because the M1 exam went well, it makes it slightly better
    I'm more confident with C4 than C3 hah xD

    (Original post by samb1234)
    Stupid person: 'i think every number is odd'
    you: 'but what about 2,4 and 6'
    Stupid person 'oh yeah'
    Ahh I thought as much haha! Nice explanation
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    (Original post by SeanFM)
    Best person to ask is someone doing it in a paper never bothered learning it in C3 (didn't know it existed, or if I did I wouldn't know it by name) and don't really remember it from first year uni stuff :hide:

    I guess contradicting a statement works.
    Ah cheers lad is there any other insertname examples or is counterexample the only one?
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    (Original post by Don Pedro K.)
    I'm more confident with C4 than C3 hah xD
    Really? I think I understand C4 more but because pretty much every question is a whole page of working out, I make far too many mistakes.
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    (Original post by particlestudent)
    Really? I think I understand C4 more but because pretty much every question is a whole page of working out, I make far too many mistakes.
    Yeah haha I'm surprised but happy about it ;p! I guess it just comes down to practice so that you make as few mistakes as possible!
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    (Original post by joodaa)
    Ah cheers lad is there any other insertname examples or is counterexample the only one?
    There's another one where you prove something to be true by showing that if it is false, there is something wrong... but I really don't think something like that would be expected of you, unless it was fairly easy/straightforward.
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    (Original post by smackitintheair)
    What kind of method marks did you miss out on? I thought usually if you get the final answer correct you get all the marks
    I got the correct answer but missed out marks because it wasn't in the uglier(!) form specified by the question so dropped one raw mark and hence 2 UMS marks.
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    For C4, do we have to know the intergration of a^x? I thought we only needed to know how to differentiate it but it's come up on question 5d on the Jan 2013 paper (I think it also came up in the 2015 one?)

    Can someone please show me how you would integrate it? I tried to use substitution (I think I set it equal to y) and then subbed the value back into my final answer but I'm not sure if this is completely correct?
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    (Original post by cookiemonster15)
    For C4, do we have to know the intergration of a^x? I thought we only needed to know how to differentiate it but it's come up on question 5d on the Jan 2013 paper (I think it also came up in the 2015 one?)

    Can someone please show me how you would integrate it? I tried to use substitution (I think I set it equal to y) and then subbed the value back into my final answer but I'm not sure if this is completely correct?
    Well, I haven't seen anything like this before but I think I may know how to do it.

    So we know that when y = 2^x for example, dy/dx = 2^xln2 (you should know how to derive this also using implicit differentiation).

    Now integrating is basically seeing how to go from "dy/dx" back to your "y". So if we have integrating 2^x, and we know that dy/dx = 2^xln2, what do we need to do to 2^xln2 in order to get just 2^x? That's right, times 2^xln2 by 1/ln2 so that the "ln2" cancels out.

    Therefore, integrating 2^x gives 2^x * 1/ln2 + c ----> 2^x/ln2 + c.

    There's probably a better explanation for this but this is my thought process !
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    (Original post by cookiemonster15)
    For C4, do we have to know the intergration of a^x? I thought we only needed to know how to differentiate it but it's come up on question 5d on the Jan 2013 paper (I think it also came up in the 2015 one?)

    Can someone please show me how you would integrate it? I tried to use substitution (I think I set it equal to y) and then subbed the value back into my final answer but I'm not sure if this is completely correct?
    This video shows an actual proof as to how to go about doing these types of questions ^_^ https://www.youtube.com/watch?v=JVIzBYGH1gQ
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    (Original post by cookiemonster15)
    For C4, do we have to know the intergration of a^x? I thought we only needed to know how to differentiate it but it's come up on question 5d on the Jan 2013 paper (I think it also came up in the 2015 one?)

    Can someone please show me how you would integrate it? I tried to use substitution (I think I set it equal to y) and then subbed the value back into my final answer but I'm not sure if this is completely correct?
    They seem to like asking this type of question a bit more in recent years. You need to think about reverse of differentiation (recognition) when answering these types of questions
    ie you know a^x differentiates to a^x lna
    so integrating a^x must go to (a^x)/lna (since you are lacking that constant had you differentiated a^x)
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    What should I be getting in C4 and C3 past papers average to get an A* in the. Actual exam?
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    (Original post by Engineerrookie)
    What should I be getting in C4 and C3 past papers average to get an A* in the. Actual exam?
    C3... maybe 72/75, around that.

    C4... 67+ I guess, because it's more difficult.

    At least, that is what I was averaging as far as I can remember
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    (Original post by SeanFM)
    C3... maybe 72/75, around that.

    C4... 67+ I guess, because it's more difficult.

    At least, that is what I was averaging as far as I can remember
    Sean, do you think we would be expected to be able to integrate something like (x)(5-x^2)?
 
 
 
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