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    (Original post by The Stig's student cousin)
    If past paper mark schemes are anything to go by its likely imo that out of the 5 marks, 3 were for the proof and two were for the sketch. I'm hoping by clearly labeled points get me 2/5 tbh.
    well, we can always hope :yep:
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    (Original post by Skadoosh)
    Well, I can't guarantee that that's the correct method as there are some conflicting views on here.

    Either way, if you applied you the correct method to find the angle between the normal to the plane and the pipe, but didn't get the correct answer for the angle between the plane and the pipe, I would say it would only be 1 or 2 marks lost max.
    I'm pretty sure your method is correct now that I look at it, I did the right calculation to find the angle between the pipe and the normal, but didn't take it away from 90. There goes my 100% :/
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    I'm surprised so many people find q3 difficult??

    y=sinthetacostheta therefore y=1/2sin2theta therefore sin2theta=2y

    You're already given x=cos2theta, so simply square the two equations and use cos^2(2theta)=sin^2(2theta)=1
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    (Original post by DeanT)
    It ended up as 2tan\theta(tan\theta - 2) \implies \theta = 0, \theta = tan^{-1}{2} = 63.43
    yep..that's exactly what I got
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    (Original post by New Username)
    yep..that's exactly what I got
    same, what did people put for the very first question
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    (Original post by clad in armour)
    same, what did people put for the very first question
    x+1 cancelled, it was something like (3x + 1)/(x^2 - 1)
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    (Original post by JoshC)
    x+1 cancelled, it was something like (3x + 1)/(x^2 - 1)
    im sure it was x-1
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    (Original post by clad in armour)
    im sure it was x-1
    it might have been, which ever was on the top and bottom
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    Was it okay in the first question to leave it the denominator as (x^2 - 1)? In the past mark schemes you sometimes lost a mark if you didn't put it as (x + 1)(x - 1)
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    for the volume of revolution, what did people get?
    i got 4/3pi
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    (Original post by work now, enjoy later)
    for the volume of revolution, what did people get?
    i got 4/3pi
    Yeah, same. \displaystyle \pi\int^1_0 1 + x^2 dx = \frac{4}{3}\pi
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    (Original post by work now, enjoy later)
    for the volume of revolution, what did people get?
    i got 4/3pi
    i was worried about that one! glad someone got the same answer at least :P
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    i got stuck on question 3 eurgh..
    about the parametic equations.
    x=cos2x y=sinXcosX

    eurgh! i used up literally 2 and a half pages trying to figure it out
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    (Original post by DeanT)
    Was it okay in the first question to leave it the denominator as (x^2 - 1)? In the past mark schemes you sometimes lost a mark if you didn't put it as (x + 1)(x - 1)
    I left it as the latter as that is the fraction in simplified form. x^2 -1 would be the result of expanding the brackets.
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    What did everyone get for the Tan question - i think it was questio 6?
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    (Original post by ELR♥)
    What did everyone get for the Tan question - i think it was questio 6?
    I think I got 0 and 60 something, you?
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    (Original post by Skadoosh)
    I'm surprised so many people find q3 difficult??

    y=sinthetacostheta therefore y=1/2sin2theta therefore sin2theta=2y

    You're already given x=cos2theta, so simply square the two equations and use cos^2(2theta)=sin^2(2theta)=1
    I did this deifferently:

    a = theta

    x = cos 2a
    = (cosa)^2 - (sina)^2
    x^2 = (cosa)^4 + (sina) ^ 4 - 2(sina)^2(cosa)^2

    + 4y2 (4(cosa)^2(sina)^2)

    = (cosa)^4 + (sina) ^ 4 + 2(sina)^2(cosa)^2

    which factorises to (cosa)^2 + (sina)^2)^2 which is obviously 1^2 = 1.

    Did anyone else do it this way and if not will I still get the marks?...
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    (Original post by rick4236)
    I think I got 0 and 60 something, you?
    YES! I got 0 and 63 I think, some of my friends said they just got 0 so I got worried haha (: Least I've found another person with the same answer as me x
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    This has been mostly reassuring thank god
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    yeah that's right.

    Values for theta for the last part of question people? I only seem to get the one in the correct domain.
 
 
 
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