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    What is the significance of this "dimple" proof in FP2? Haven't really seen it anywhere else and nothing listed in the spec.
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    (Original post by paradoxequation)
    What is the significance of this "dimple" proof in FP2? Haven't really seen it anywhere else and nothing listed in the spec.
    So you understand some of the maths going on and not blindly accept all the facts given.


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    (Original post by physicsmaths)
    So you understand some of the maths going on and not blindly accept all the facts given.


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    Could we be asked to prove it?
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    (Original post by somevirtualguy)
    Could we be asked to prove it?
    Possibly if I recall correctly
    It pretty much proves itself once you remember the initial reasoning about tangents though so just make sure you understand that
    Though it's very unlikely to come up and if it did would probably give a bit of guidance
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    Do we need to know the proofs for multiplying and dividing complex numbers? Thanks.
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    (Original post by jtt1998)
    Hi, does anybody have a link to the January 2016 IAL paper and mark scheme??
    Sorry if this has already been posted, I can't find it anywhere!
    I asked my teacher and she said that there wasn't IAL paper last January.
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    (Original post by paradoxequation)
    What is the significance of this "dimple" proof in FP2? Haven't really seen it anywhere else and nothing listed in the spec.
    I think it's purely there to help you understand two things:
    1. Use of finding tangents parallel & perpendicular to the initial line (stuff you're expected to know)
    2. Sketching polar curves (you may get a mark for clearly showing the dimple or cardiod shape of your sketch).
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    How do i do part a of this question? The MS is here but I don't understand why or how they did what they did.

    https://8dedc505ac3fba908c50836f5905...%20Edexcel.pdf
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    Can someone show me step by step how they'd differentiate dy/dz wrt x?
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    [QUOTE=coolguy123456;65489151]Name:  Screen Shot 2016-06-06 at 09.55.24.png
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    How do i do part a of this question? The MS is here but I don't understand why or how they did what they did.

    https://8dedc505ac3fba908c50836f5905...%20Edexcel.pdf[/QUOTE
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    (Original post by coolguy123456)
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    How do i do part a of this question? The MS is here but I don't understand why or how they did what they did.

    https://8dedc505ac3fba908c50836f5905...%20Edexcel.pdf
    So 120/(2-t) is the coefficient of S, and as dS/dt is on its own we can say the Integrating Factor is the integral of 120/(2-t)... Then approach as you would
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    What is this form??? It's from the spec
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    (Original post by somevirtualguy)
    So 120/(2-t) is the coefficient of S, and as dS/dt is on its own we can say the Integrating Factor is the integral of 120/(2-t)... Then approach as you would
    Thank you both, I didn't realise we had to use an integrating factor, understood straight away once i read the words "integrating factor" 😂
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    (Original post by Kvothe the arcane)
    Can someone show me step by step how they'd differentiate dy/dz wrt x?
    d/dx(dy/dz) = d^2y/dz^2 * dz/dx
    As an overall we want to end up with it being with respect to x, so the dzs effectively cancel.

    if we were to differentiate again

    d^3y/dz^3 * (dz/dx)^2 + d^2y/dz^2 * d^2z/dx^2

    Please correct me if wrong I always struggle to visualise it on my phone
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    (Original post by Jackmleitch)
    What is this form??? It's from the spec
    Just realised its just:
    2cosx = z + 1/z
    2isinx = z - 1/z
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    For nth roots of a complex equation. does the value of theta used for k = 0, 1, 2, etc. always have to be between pi and -pi?
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    (Original post by Nikhilm)
    For nth roots of a complex equation. does the value of theta used for k = 0, 1, 2, etc. always have to be between pi and -pi?
    it needs to be between the boundaries stated at the start. either pi -> -pi or 0->2pi
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    (Original post by Tizzydag)
    it needs to be between the boundaries stated at the start. either pi -> -pi or 0->2pi
    Normally there are no boundaries, so I assume that since it's an argument it's assumed pi to -pi?
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    (Original post by Kvothe the arcane)
    Can someone show me step by step how they'd differentiate dy/dz wrt x?


    Think of it as if the dz's cancel each other out in the second line.
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    Thanks Ayman!.

    I guess I see it now (though not directly).

    I guess I'll use a temporary sub to make it easier to see. I asked because it was in 2014(R) Q 8.
 
 
 
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