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    (Original post by economicss)
    Please could anyone do a worked solution for question 12a https://8dedc505ac3fba908c50836f5905...%20Edexcel.pdf I've tried it by substituting in for lambda plus lambda i when x is greater than 0 but for some reason I can't get it to work but I thought the method was correct? Thanks
    for part a you just literally show that |(lamda+1) lamda i| =|(lamda+1)i +lamda| ( circle equation )
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    Aside from proving De Moivre's Theorem using proof by induction, and then the little routine for showing it's also true for negative integers, are there any other proofs they could ask us to do? I'm aware of the differential proofs they could ask, like showing d^n/dx^n(xe^x)=(n+x)e^x, but is there anything else?
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    (Original post by economicss)
    Please could anyone do a worked solution for question 12a https://8dedc505ac3fba908c50836f5905...%20Edexcel.pdf I've tried it by substituting in for lambda plus lambda i when x is greater than 0 but for some reason I can't get it to work but I thought the method was correct? Thanks
    just done it and got the final answer. phone being awkward n not letting me post. rearrange T for z=.... then sub w=u+iv. multiply fraction by conjugate of denominator etc etc. (don't bother to multiply out denominator...you should see why) then equate x=f(u,v), y=g(u,v) and use fact that y=x. clean up algebra and you should get u^2+v^2=1. be careful with algebra. or be a little clever with algebra and see below
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    (Original post by economicss)
    Please could anyone do a worked solution for question 12a https://8dedc505ac3fba908c50836f5905...%20Edexcel.pdf I've tried it by substituting in for lambda plus lambda i when x is greater than 0 but for some reason I can't get it to work but I thought the method was correct? Thanks
    No one else did one, so here is what I got.

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    (Original post by somevirtualguy)
    Aside from proving De Moivre's Theorem using proof by induction, and then the little routine for showing it's also true for negative integers, are there any other proofs they could ask us to do? I'm aware of the differential proofs they could ask, like showing d^n/dx^n(xe^x)=(n+x)e^x, but is there anything else?
    don't think so, check spec if unsure
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    (Original post by Nirm)
    Anyone know a clear solution for question 4 part B of the June 2015 paper? The question seems really confusing and I don't really understand arsey's working and can't find the official mark scheme either.
    My solution:
    Name:  ImageUploadedByStudent Room1465316582.652052.jpg
Views: 128
Size:  152.4 KBName:  ImageUploadedByStudent Room1465316619.789753.jpg
Views: 133
Size:  150.6 KB



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    (Original post by anndz3007)
    Attachment 545355
    Im a little confused, in this question, to find the length OP the mark scheme worked out r
    Attachment 545355545357 but in this question, the length of PS is y instead of r
    both lines are parallel to the initial line .
    Simply because on the first question you want to find the distance from the origin to the point, and on the second question you want to find the height from the axis to the tangent. It can be done many ways, but the easiest is to substitute it in to the y equation.
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    (Original post by economicss)
    Please could anyone do a worked solution for question 12a https://8dedc505ac3fba908c50836f5905...%20Edexcel.pdf I've tried it by substituting in for lambda plus lambda i when x is greater than 0 but for some reason I can't get it to work but I thought the method was correct? Thanks
    http://imgur.com/AjvZK9Q

    There ya go buddy
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    For second order complementary function can we write the aux function straight up or do we need to say let y=e^mx etc..?
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    (Original post by khaleesi98)
    Yeah that's it, just carry on until you have 5 different x values
    Well thats just long tbh but i guess thats al i can do, thanks a lot!
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    (Original post by Rkai01)
    For second order complementary function can we write the aux function straight up or do we need to say let y=e^mx etc..?
    You need to write the aux function, for example m2 + 4m + 4 then values you get to put it into the write equation.

    y=λemx is for the Particular integral?

    Does this answer your question?
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    (Original post by economicss)
    Please could anyone do a worked solution for question 12a https://8dedc505ac3fba908c50836f5905...%20Edexcel.pdf I've tried it by substituting in for lambda plus lambda i when x is greater than 0 but for some reason I can't get it to work but I thought the method was correct? Thanks
    Here's my way worse method using u+iv:
    Name:  ImageUploadedByStudent Room1465317464.441976.jpg
Views: 118
Size:  147.5 KB

    the key to this question is getting
    arg(z) = pi/4
    arctan(y/X) = pi/4
    y/x = 1
    y = X

    Then it's just a simple matter of mapping y=x with whatever method you're comfortable with



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    Does anyone have a link to the 2015 R and normal paper.
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    How do you feel about doing M1 and FP2 back to back!! (typical edexcel)
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    (Original post by Louisb19)
    Does anyone have a link to the 2015 R and normal paper.
    I dont think there's a 2015 R, but if you find one could you let me know please.

    also: http://qualifications.pearson.com/co...e_20150603.pdf
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    (Original post by thatapanydude)
    How do you feel about doing M1 and FP2 back to back!! (typical edexcel)
    Clashes always suck, luckily I did M1 last year, but this year I have to do D1 then M2 back to back.
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    (Original post by Rkai01)
    For second order complementary function can we write the aux function straight up or do we need to say let y=e^mx etc..?
    Are you asking if you HAVE write y = e^mx or you will lose marks? I think it would be better to just state it beforehand just in case, just for clarity.
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    (Original post by somevirtualguy)
    Aside from proving De Moivre's Theorem using proof by induction, and then the little routine for showing it's also true for negative integers, are there any other proofs they could ask us to do? I'm aware of the differential proofs they could ask, like showing d^n/dx^n(xe^x)=(n+x)e^x, but is there anything else?
    http://www.ctralie.com/Teaching/Euler/

    I think the taylor series one or the differential equation one could come up, but it would cause a lot of outrage from students round the country. Since its not explicitly listed as something you need to know
    The only thing you need to know really is proof of DMT.
    But they could ask you a PBF for a taylor series, where you have some ln function with a factorial in it, just remember n*(n-1)!=n! its pretty obvious but I wasnt told this specifically.
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    (Original post by TheMarshmallows)
    Clashes always suck, luckily I did M1 last year, but this year I have to do D1 then M2 back to back.
    I've got both clashes: I'm resitting M1 and I've had a new teacher this year who can teach D1 and D2 so rather than attempt FP3 or S3 I'm doing that. And the worst thing is I've seen some days on Edexcel's exam timetable that have no exams in the morning (or afternoon)!
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    (Original post by kennz)
    http://www.ctralie.com/Teaching/Euler/

    I think the taylor series one or the differential equation one could come up, but it would cause a lot of outrage from students round the country. Since its not explicitly listed as something you need to know
    The only thing you need to know really is proof of DMT.
    But they could ask you a PBF for a taylor series, where you have some ln function with a factorial in it, just remember n*(n-1)!=n! its pretty obvious but I wasnt told this specifically.
    I highly doubt we will be asked these, though the link you provided is really good. Thanks for sharing.
 
 
 
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