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Edexcel A2 C4 Mathematics June 2016 - Official Thread Watch

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    (Original post by maruchan)
    Yep maybe it might be a cone or a sphere
    whens yours??
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    (Original post by M&F)
    can someone please explain part a of Q6 please. I dont undestand how they get tan30 = r/h????

    https://5c59854d0ccd29d489c9e5e689a8...%20Edexcel.pdf
    Draw a line from the bottom of the vase, vertically up. The angle between each side of this line and the vase is 30 degrees. You should be able to recognise the right-angled triangles that appear, with sides h, r, and the side of the vase.

    tan30 = opposite/adjacent = r/h.
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    (Original post by raman_17)
    whens yours??
    tomorrow
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    (Original post by XxKingSniprxX)
    % error calculated by doing say (area of integral-area of trap/area of trap)x100?

    ^ Can someone else confirm that's right just want to confirm/double check/reassurance
    it's (change/original) *100
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    (Original post by XxKingSniprxX)
    % error calculated by doing say (area of integral-area of trap/area of trap)x100?

    ^ Can someone else confirm that's right just want to confirm/double check/reassurance
    that is correct
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    2015 question 8) b), how you get 2 and 0 as limits? Anyone? Please and Thank you!
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    Please can someone help me with vectors? In the textbook it says when you are working out the angle between two lines, the direction of the vectors must be going away from the angle. However in lots of PPQs this doesn't apply - am I missing something?
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    (Original post by maruchan)
    tomorrow
    nice

    this c34 2016 IAL paper is beautiful
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    Seriously hope they don't ask a difficult rates and differential equations question :/
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    (Original post by LilacFlorence)
    Please can someone help me with vectors? In the textbook it says when you are working out the angle between two lines, the direction of the vectors must be going away from the angle. However in lots of PPQs this doesn't apply - am I missing something?
    They have to be in the same direction so either both inwards or both outwards
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    Guys nothing related to c4 but do any of u remember the proof that we had to do for cotx in c3?
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    (Original post by raman_17)
    that is correct
    No it isn't, it's over original which means true value, not area of trap
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    (Original post by LilacFlorence)
    Please can someone help me with vectors? In the textbook it says when you are working out the angle between two lines, the direction of the vectors must be going away from the angle. However in lots of PPQs this doesn't apply - am I missing something?
    As far as I know, it does apply? for example if you have the intersection point C, and two points A and B on either of the two lines, to work out the angle ACB, you can use the vectors CA and CB (as the direction of these vectors go away from the angle)!

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    An integral I constructed for those who might be interested:

    \displaystyle \int_{\phi}^{\varphi }\sin\left ( \alpha x \right )e^{\left [ q\sin\left ( px \right ) \right ]^{2}} \ \mathrm{d}x

    where \alpha = 2p.
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    (Original post by leestitt)
    Yeah, rates of change didnt come up last year either, I have a feeling it will be trapezium rule, followed by area under a curve, then followed by percentage error
    For percentage error is the equation (approx-real)/real x100 or (real-approx)/real x100
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    (Original post by eftio.gea)
    Guys nothing related to c4 but do any of u remember the proof that we had to do for cotx in c3?
    dont remember the question exactly but it onlved to fractions both with a denominator of tanx. One of the numerators was cosec^2 x which you replace with 1-tan^2 x and the other numberator was tan^x. the tan^x cancelled out after adding the fractions leavcing you with 1/tanx = cotx
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    (Original post by coolguy123456)
    No it isn't, it's over original which means true value, not area of trap
    from the book it's (area using trapezium rule - integral calculation/integral calculation) x100
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    (Original post by joodaa)
    For percentage error is the equation (approx-real)/real x100 or (real-approx)/real x100
    Yes
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    (Original post by LilacFlorence)
    Please can someone help me with vectors? In the textbook it says when you are working out the angle between two lines, the direction of the vectors must be going away from the angle. However in lots of PPQs this doesn't apply - am I missing something?
    (Original post by Don Pedro K.)
    As far as I know, it does apply? for example if you have the intersection point C, and two points A and B on either of the two lines, to work out the angle ACB, you can use the vectors CA and CB (as the direction of these vectors go away from the angle)!

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    You could also use AC and BC

    Or if you used AC and CB (or BC and CA), you'd be working out the bigger angle between the two vectors, so you'd just do 180-(that)
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    This sounds so stupid, but integrating 1/something is confusing me in that the denominator has to be the power of 1 to use ln?? How would I integrate this please
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