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    Sorry got held up with work problem.

    Answers are here:

    http://www.thestudentroom.co.uk/show...7#post29464347

    I started a new thread as I thought newcomers would not find them buried on page 14.
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    (Original post by ElMoro)
    I didn't check your method but your answer was the same as mine
    This is how i did it with the same answer.

    tan x= 1/4 tan 2x = (expanded out and sub in tan x= 1/4) = 8/15 tan 4x = tan(2x+2x) (expanded out and sub in tan 2x = 8/15) = 240/161
    cot 2x = 1/tan2x = 15/8 then times together 1/4 x 15/8 x 240/161 = 225/322
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    mr M??????/
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    from the feedback, it looks like it was a hard paper. Anywayz, God forbid, if any of you didn't get the grade you wanted. You will find it 'piss easy' after you have studied core 4 along which you can re take C3 in June.

    Did any one do M1 today?
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    (Original post by jackdelderfield)
    I differentiated (lnx)^2 differently cause it was in brackets, so mine came out at 2x1/x(lnx).
    i used chain rule to differentiate the lnx^2 but I couldnt get the right answer. I used my calculator to find out the decimal answer but the exact answers I got never came out correct! Hoping that I got some marks for working!did anyone manage to differentiate lnx^2 correctly for this question?
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    (Original post by Flint_09)
    every1 how did you find this paper overall on a scale of 1-10 with 1 being the easiest and 10 the hardest!
    11 ?
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    (Original post by DaveGBG)
    11 ?
    oh 110%!
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    (Original post by godexists1234)
    balls! i forgot to write pi in the volume of revolution thing =[ (i always do that)
    but all the answers ive seen here look familiar so otherwise im feeling good
    Same! I got it all right but forgot the pi! argh.
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    was this the answer for 7(ii)?:

    the function with an inverse is f(x) and the inverse is f^-1(x)= e^x

    and for 7(iii) 1/e^3
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    Evil paper, i'm now waving goodbye to my B in maths
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    (Original post by Princess_perfect786)
    was this the answer for 7(ii)?:

    the function with an inverse is f(x) and the inverse is f^-1(x)= e^x

    and for 7(iii) 1/e^3
    http://www.thestudentroom.co.uk/show...7#post29464347
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    (Original post by jackdelderfield)
    Interesting. Substituting e^3 seems to give the same answer from both, 6/e^3?
    yup i think i got that
    i was just wondering if there was a beter way of differentiating it
    ...now i think of it a substitution u = lnx might have worked lol
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    (Original post by Princess_perfect786)
    was this the answer for 7(ii)?:

    the function with an inverse is f(x) and the inverse is f^-1(x)= e^x

    and for 7(iii) 1/e^3
    (ii) is correct.

    (iii) is 6/e^3.
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    To be honest, having just worked through the paper in an hour or so, I don't think it was that hard at all. The last question required a little ingenuity but this paper was about as difficult as the other two 2010 papers, in my opinion. I'd expect exam conditions would have added about 20 mins to my time taken to work through the paper.
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    (Original post by Farhan.Hanif93)
    To be honest, having just worked through the paper in an hour or so, I don't think it was that hard at all. The last question required a little ingenuity but this paper was about as difficult as the other two 2010 papers, in my opinion. I'd expect exam conditions would have added about 20 mins to my time taken to work through the paper.
    IMO, the paper wasn't too difficult however I would say quite a few questions were unusual/unexpected but no necessarily difficult.
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    (Original post by DaveGBG)
    Anyone else have a time issue with this paper?
    I had a complete time issue!
    When they said 5 minutes left I wanted to cry
    I did have a stab at all the questions but no time to check my answers and I needed to go back a sort some out

    So annoyed with this exam!
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    (Original post by Princess_perfect786)
    was this the answer for 7(ii)?:

    the function with an inverse is f(x) and the inverse is f^-1(x)= e^x

    and for 7(iii) 1/e^3
    Answers are here: http://www.thestudentroom.co.uk/show...php?p=29465143

    for 7(iii)

    gf(x) = (lnx)^2 + 8



let u = lnx

    \frac{du}{dx} = \frac {1}{x}

    gf(x) = u^2 +8

    \frac{dy}{du} = 2u = 2lnx

    \frac{dy}{dx} = \frac{dy}{du} \times \frac{du}{dx} = \frac{1}{x} \times 2lnx

    x = e^3 ; \frac {2ln(e^3)}{e^3} = \frac{2 \times 3}{e^3}
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    (Original post by Farhan.Hanif93)
    To be honest, having just worked through the paper in an hour or so, I don't think it was that hard at all. The last question required a little ingenuity but this paper was about as difficult as the other two 2010 papers, in my opinion. I'd expect exam conditions would have added about 20 mins to my time taken to work through the paper.
    Where did you get the paper?
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    (Original post by tpowertj)
    Where did you get the paper?
    Someone posted it on here. Dig through the C3 threads.
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    (Original post by Revolution is my Name)
    45,000, I think.
    Did you write it as 4.5 x 10^4 since it said 2.s.f and there is no way of telling if you write it like that? Also were units essential on this question? I can't remember at all if I put them.
 
 
 
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