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Edexcel A2 C4 Mathematics June 2016 - Official Thread Watch

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    (Original post by k.russell)
    Wow was that 2016 January? I saw that had crazy high UMS boundaries - still I would be over the moon if I can get a 98% UMS average in my core congratulations - did you do international M2?
    I was particularly annoyed because the only reason I dropped a mark was because I gave a correct answer in a slightly neater form than was asked for in the question, one mark dropped. Annoying.

    Yeah, I did international C1-4, M1-3, S1-3, FP1-3.
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    Hi Zacken. Sorry to disturb you but just wondering will I get the correct marks for this method if I get the right answer:

    So for finding the solutions I don't use the cast diagram, but a set of rules.

    E.g. for cos: do 360- etc

    Because some Qs say "Solutions based entirely on graphical or numerical methods are not acceptible"

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    (Original post by KINGYusuf)
    Hi Zacken. Sorry to disturb you but just wondering will I get the correct marks for this method if I get the right answer:

    So for finding the solutions I don't use the cast diagram, but a set of rules.

    E.g. for cos: do 360- etc

    Because some Qs say "Solutions based entirely on graphical or numerical methods are not acceptible"

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    That's fine, you just can't use iterative methods or trial and error.
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    Tyvm

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    Fml I barely had any time to revise for C4 and S2, I'm completely fcked, I just started vectors for the first time and I'm rubbish at them. Bye bye university, just bye bye a good future my parents will kill me
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    Lol dw. I crammed M1 in like 2 days and mastered Vectors in 1

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    (Original post by KINGYusuf)
    Lol dw. I crammed M1 in like 2 days and mastered Vectors in 1

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    Htf did you do that? What resources did you use?


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    Exam Solution and did most of the Qs kn the textbook

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    In c4 solomon A can anyone explain to be how to do question 6a?
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    (Original post by Ainsleyy)
    In c4 solomon A can anyone explain to be how to do question 6a?


    I hope this is clear enough!
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    (Original post by Ainsleyy)
    In c4 solomon A can anyone explain to be how to do question 6a?
    Use the funky angle splitting formulas from C3
    Basically the idea is that cos(5x) = cos(3x + 2x) = cos3xcos2x - sin3xsin2x
    while cos(x) = cos(3x - 2x) = cos3xcos2x + sin3xsin2x
    Hence cos(x) - cos(5x) = 2sin3xsin2x
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    (Original post by Ainsleyy)
    In c4 solomon A can anyone explain to be how to do question 6a?
    Use the product to sum identities:
    This one-------cosP-cosQ
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    Thanks everyone. Should I know that I have to use some kind of identity because we cant integrate it straight away? and then just look through the identities till i find one that fits? or should I remember that specific example?
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    (Original post by Ainsleyy)
    Thanks everyone. Should I know that I have to use some kind of identity because we cant integrate it straight away? and then just look through the identities till i find one that fits? or should I remember that specific example?
    You should remember that if you have something like sin(px)sin(qx) or sin(px)cos(qx) you can use those identities on it
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    (Original post by 13 1 20 8 42)
    Use the funky angle splitting formulas from C3
    Basically the idea is that cos(5x) = cos(3x + 2x) = cos3xcos2x - sin3xsin2x
    while cos(x) = cos(3x - 2x) = cos3xcos2x + sin3xsin2x
    Hence cos(x) - cos(5x) = 2sin3xsin2x
    Is this like a standard integral that we could expect :/? I've never seen the factor formula been used before except maybe once XD
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    13 1 20 8 42 Also, would it not be possible to use the cosA - CosB = -2Sin(A+B/2)Sin(A-B/2) expression?

    So -1/2[Cos4x - Cos2x] = Sin3xSin2x?
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    (Original post by Don Pedro K.)
    Is this like a standard integral that we could expect :/? I've never seen the factor formula been used before except maybe once XD
    It is unlikely. Solomon papers have a habit of being a bit "off" relative to what you should expect. However it is good to know this integral. I think it came up in FP2 last year and the integration in that is all just C4 level (further integration starts in FP3) so it seems Edexcel are willing to use it.
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    (Original post by 13 1 20 8 42)
    It is unlikely. Solomon papers have a habit of being a bit "off" relative to what you should expect. However it is good to know this integral. I think it came up in FP2 last year and the integration in that is all just C4 level (further integration starts in FP3) so it seems Edexcel are willing to use it.
    Okay, I will keep it in mind. I have a feeling Edexcel may decide to continue their streak of stupidity this year and pull something like this out of the bag... XD
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    (Original post by Don Pedro K.)
    13 1 20 8 42 Also, would it not be possible to use the cosA - CosB = -2Sin(A+B/2)Sin(A-B/2) expression?

    So -1/2[Cos4x - Cos2x] = Sin3xSin2x?
    That is the expression being used essentially. But A = 4x, B = 2x gives (A - B)/2 = 2x/2 = x, not 2x; you need A = 5x and B = x
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    (Original post by 13 1 20 8 42)
    That is the expression being used essentially. But A = 4x, B = 2x gives (A - B)/2 = 2x/2 = x, not 2x; you need A = 5x and B = x
    ahhh whoops okay yeah that's a mistake on my part xD Sorry
 
 
 
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