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Edexcel FP2 Official 2016 Exam Thread - 8th June 2016 watch

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    (Original post by economicss)
    Thanks for this, just to check, is it the case that for any second order de with repeated roots that you multiply the PI by t or do you only do this if your second order de has repeated roots and contains one of the terms of the PI you were going to use? Thanks
    (Original post by EmmaLouise759)
    Is this always the case with repeated roots?
    No. You only do this when there are repeated roots and your default PI contains a term from your CF.
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    (Original post by Zacken)
    No. You only do this when there are repeated roots and your default PI contains a term from your CF.
    Great, got it, thanks
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    (Original post by Zacken)
    No. You only do this when there are repeated roots and your default PI contains a term from your CF.
    Are there any other rules like this for SO DEs? I'd never heard of this until now...
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    (Original post by somevirtualguy)
    Are there any other rules like this for SO DEs? I'd never heard of this until now...
    I don't think there's any off the top of my head... just remember the standard particular integral forms and modify them as discussed. I can't think of any other rules.

    They tend to just give you the more complicated particular integrals in the exam anyway. So if this was an exam question, the particular integral would be given to you.
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    (Original post by oinkk)
    I don't think there's any off the top of my head... just remember the standard particular integral forms and modify them as discussed. I can't think of any other rules.

    They tend to just give you the more complicated particular integrals in the exam anyway. So if this was an exam question, the particular integral would be given to you.
    Ah okay thanks for the help
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    (Original post by Craig1998)
    I'm not sure about 29b, all they seem to have done is found an equation of the circle to which the locus is a major arc. I've never seen a question like that, maybe somebody else can help..

    For example 30, you have a point at (0, 0) and a point at (0, 4i), these will form the points of your arc. This question is unique as the angle given is \frac\pi2 which means that there will be a right angle between each point and your point P, which leads to your arc just being a semi circle. Therefore, it would lead you to draw a semi circle from (0, 0) to (0, 4i) or vice versa, where your point P forms a right angle. I hope this explains it.

    For example 31, the minimum and maximum points of |z| are the points which are nearest and furthest from the origin. As your circle is essentially given (radius 3 and centre (12, 5)), and the distance from the origin to the centre can be worked out using pythagoras (\sqrt{12^2 + 5^2} = 12, you can add 3 and subtract 3 (the radius) to find the minimum and maximum points.
    I need help with another question pls .

    page 59 1b and c:
    For the transformation w = z + 4 + 3i, sketch on separate argand diagrams the locus of w when:
    b) z lies on the half life arg z = pi/2
    c) z lies on the line y = x

    I know how to do part a) as a similar example is in the book but dont know b and c.
    Cheers
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    (Original post by fpmaniac)
    I need help with another question pls .

    page 59 1b and c:
    For the transformation w = z + 4 + 3i, sketch on separate argand diagrams the locus of w when:
    b) z lies on the half life arg z = pi/2
    c) z lies on the line y = x

    I know how to do part a) as a similar example is in the book but dont know b and c.
    Cheers
    We know that w=z+a+ib represents a translation by a units along the real axis, b units up the imaginary axis.

    And for part c, it's just a standard transformations question where you let z=x+iy=x+ix.

    Does that help?
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    Please could anyone explain how to do question 9b, I get how to work out the area of the sector but I can't think how to find the bit of the shape which is to the left of the origin? Thanks Name:  image.jpg
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    (Original post by fpmaniac)
    I need help with another question pls .page 59 1b and c:For the transformation w = z + 4 + 3i, sketch on separate argand diagrams the locus of w when:b) z lies on the half life arg z = pi/2c) z lies on the line y = x
    I know how to do part a) as a similar example is in the book but dont know b and c.Cheers
    Part b, you can tell that the transformation is of the form, a specific format in the book.
    And for part c, here, you can see my working The general rule of thumb for complex transformations, is to either make z the subject (normally if its a circle) or to use the given condition. Here, we have to use the latter, since it gives us the condition that y=x, which means the real parts of the transformed complex number must be equal to the imaginary part of the same transformed complex number. As shown here.

    Name:  IMAG5064.jpg
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    (Original post by economicss)
    Please could anyone explain how to do question 9b, I get how to work out the area of the sector but I can't think how to find the bit of the shape which is to the left of the origin? Thanks Name:  image.jpg
Views: 141
Size:  512.3 KB
    If I understood what you mean correctly, it's still part of the same shape of curve C1, so just integrate the whole of curve C1 between the points of intersection (between the positive point of intersection and negative point of intersection, whatever the angle it is).


    Edit: Many beat me to it :P
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    (Original post by economicss)
    Please could anyone explain how to do question 9b, I get how to work out the area of the sector but I can't think how to find the bit of the shape which is to the left of the origin? Thanks Name:  image.jpg
Views: 141
Size:  512.3 KB
    I'd use the symmetry of the curves (i.e., deal with everything above the initial line, then double at the end).

    Work out the area bounded by the sector above the initial line (C2 formula), and then integrate the curve C1 between pi/3 and pi.

    ... and then double your answer to that.
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    Hi,

    Can someone help me understand how they solved Mixed Ex 4E q 8?

    dy/dx + 2xy = x

    I've tried doing it, and I get e^x^2 as the I.F, but I later end up having to integrate x(e^x^2), but how can this be possible if the I.F cannot be integrated?

    Thanks for your help in advance

    Edit: Never mind, I understand it now!! Thanks!
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    (Original post by tripleseven)
    Hi,

    Can someone help me understand how they solved Mixed Ex 4E q 8?

    dy/dx + 2xy = x

    I've tried doing it, and I get e^x^2 as the I.F, but I later end up having to integrate x(e^x^2), but how can this be possible if the I.F cannot be integrated?

    Thanks for your help in advance
    use the sub u=x^2 in that integral if you can't do it by recognition.
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    (Original post by tripleseven)
    Hi,

    Can someone help me understand how they solved Mixed Ex 4E q 8?

    dy/dx + 2xy = x

    I've tried doing it, and I get e^x^2 as the I.F, but I later end up having to integrate x(e^x^2), but how can this be possible if the I.F cannot be integrated?

    Thanks for your help in advance

    Edit: Never mind, I understand it now!! Thanks!
    Try u=x^{2}
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    (Original post by oinkk)
    Yes, I would certainly multiply the whole thing by x. What paper is that from?
    From the FP2 resources by Arsey on TSR - Practice Paper B
    I hate these adapted questions from the old spec because there're so many mistakes
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    (Original post by Nerrad)
    From the FP2 resources by Arsey on TSR - Practice Paper B
    I hate these adapted questions from the old spec because there're so many mistakes
    Do you have a link to this? I'm running out of FP2 resources (just going through the old paper q's on physicsandmathstutor at the moment).
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    (Original post by Craig1998)
    Do you have a link to this? I'm running out of FP2 resources (just going through the old paper q's on physicsandmathstutor at the moment).
    http://www.thestudentroom.co.uk/show....php?t=2693475
    Mind you I'm finding some mistakes in the mark schemes which leads to occasional existential crisis since I don't even know when I'm right or wrong lol. Use at your own risk.
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    (Original post by economicss)
    Please could anyone explain how to do question 19b and 19d here, really struggling with them! Thanks Attachment 540593
    Hey which text book is this? Sorry to bother you
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    (Original post by tripleseven)
    Hey which text book is this? Sorry to bother you
    No problem, it's Further Pure 2 by Mark Rowland
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    Hi, does anyone know please whether the integral in question 6 here is on the spec http://madasmaths.com/archive/maths_...stitutions.pdf as I've not seen an integral that leads to arctan as the answer before? Thanks
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    (Original post by economicss)
    Hi, does anyone know please whether the integral in question 6 here is on the spec http://madasmaths.com/archive/maths_...stitutions.pdf as I've not seen an integral that leads to arctan as the answer before? Thanks
    I assume not as it is not covered in the Pearson edexcel textbook however the specification does not state which integrals can come up so I don't know for sure.

    Someone else may have a better answer for you.
 
 
 
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