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    (Original post by drandy76)
    Will need a sounding bound while I try wrap my head around group theory doe


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    please do...
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    (Original post by Cnoel)
    Anybody got final answer for the last part of 4? The sum from infinity to negative infinity
    Zacken (and myself) got 2 cosech y
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    (Original post by IrrationalRoot)
    Ok thanks, and what was the method for (ii)? I differentiated and deduced that Q(x) must have a factor of 1+x and further deduced that degP=degQ-1 (not sure if correct, pretty sure pointless anyway). Any marks at all for that?
    Yeah, all along the right lines. Reckon you'd pick up 16 marks or so on Q3.
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    (Original post by IrrationalRoot)
    Ah I see, I also did parts but then took like a side and a half of crazy manipulations to get the answer lol.
    I was considering going along that route but then saw that if I applied the trig sub, the reduction formula fell out in 5 lines.
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    (Original post by Zacken)
    Yeah, all along the right lines. Reckon you'd pick up 16 marks or so on Q3.
    Wow that's brilliant, thanks . What was the rest of the solution then if you don't mind? I didn't know where I was going with it lol.
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    (Original post by Mathemagicien)
    Zacken (and myself) got 2 cosech y
    Welp did not get that, thank you anyways haha
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    (Original post by Zacken)
    I was considering going along that route but then saw that if I applied the trig sub, the reduction formula fell out in 5 lines.
    FFS. I considered the trig sub for a split second and was like nah. Whyyyyyy.

    Anyway, I found the induction to be very short. Just a little manipulation of the factorials was all, so that made up for the mass of algebra for (ii) lol.
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    (Original post by mathsman22)
    Could someone estimate this please?
    13 + 5 + 16 + 15 + Q9 = 49 + Q9 - so a high 2 or low 1 depending on Q9.
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    (Original post by IrrationalRoot)
    Wow that's brilliant, thanks . What was the rest of the solution then if you don't mind? I didn't know where I was going with it lol.
    I think what I then did was subbed in Q(x) = (x+1)R(x) and worked along there to get a contradiction about the degrees of Q and P but I don't think what I did was correct, so I'm in the dark here as well.

    And yeah, the induction bit was pretty nice - I took up a page outlining every step because I wanted to ensure full marks on that Q at least. :lol:
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    (Original post by Zacken)
    Oof, I wish my grades were as good as yours. I really flopped STEP II. Anywho, thanks. Good luck to you.
    Np, and thanks

    EDIT : And just to add it's unlikely I've done better than you haha ( and I am still 16 )
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    But seriously it's over for me haha. Can we discuss it yet?
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    (Original post by physicsmaths)
    Having sat this and last years in exam conditions(so people can't say ur bias blah blah blah).
    This year was harder, Induction was harder. Q3 was probably the easiest and Q8 to pick up he most marks other then that the questions weren't easy to pick up marks on. I guess
    62 for Grade 1, 85 for an S. I was on the money with my predictions last year. Tbh it could stump lower then this.


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    Oh forgot to tell you that shamika predicts the same like you: 65 for grade 1 and 85 for an S grade.


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    Okay sorry been busy how did everyone find it! Would love to know how you all went on.

    I surprisingly found it decent, but I cannot for the life of me remember the questions. I think I did Q1,2,3,8 or something like that.
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    Just realised I took sech to be an ODD function for the whole of Q4. I can't believe this. Properly annoyed now, I won't even get method marks because what I did was so stupid, I subbed x=e^2y to get an equation and then I said replace y with -y and using the fact that sech is odd, you get the result. Will I lose all the marks?
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    (Original post by Zacken)
    I was considering going along that route but then saw that if I applied the trig sub, the reduction formula fell out in 5 lines.
    Ah, I feel stupid. Still, I think just brute forcing it turned out to be more time efficient than actually thinking about it
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    What would I get with this?

    1 - full
    2 - did everything up to showing that the minimum distance was whatever (at least I think I got it right, I ended up with T being x = -a).
    3 - did part (i), and showed that Q had a factor of (x +1) and that its degree was one more than P's.
    7 - showed the first part in what seemed like a bit of a dodgy way, basically just quoting the roots of unity expression from the formula booklet
    8 - did (i) and (ii), but verified g(x) by subbing it in rather than deriving it.
    12 - full
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    (Original post by Zacken)
    I think what I then did was subbed in Q(x) = (x+1)R(x) and worked along there to get a contradiction about the degrees of Q and P but I don't think what I did was correct, so I'm in the dark here as well.

    And yeah, the induction bit was pretty nice - I took up a page outlining every step because I wanted to ensure full marks on that Q at least. :lol:
    Yeh i did the induction very clearly outloning 4=2^2 n wverything haha


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    (Original post by Zacken)
    I think what I then did was subbed in Q(x) = (x+1)R(x) and worked along there to get a contradiction about the degrees of Q and P but I don't think what I did was correct, so I'm in the dark here as well.

    And yeah, the induction bit was pretty nice - I took up a page outlining every step because I wanted to ensure full marks on that Q at least. :lol:
    I generalised it to Q(x)=(x+1)^n R(x), because at the time I was worried that it would have been possible to have a factor of (x+1) in the numerator. Was this a waste of time?
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    Anyone estimate my score/grade please?

    Q1- did part i fully (the substitution) but thats it
    Q2- completed (thought this was the easiest question on the paper, surprised more people didn't do it, or maybe I'm just better with parabolas than I thought)
    Q3- completed
    Q5- only had like 5 mins left so wrote out the binomial expansion and a few inequalities in the hope it might be worth some marks
    Q6- did up to part ii fine, attempted part iii but don't feel very confident about it and don't think i really proved the conditions were N & S
    Q8- did all but the last part however i proved the equations by taking what they said g(x) was and putting it into the equation to prove it worked, which i thought would be ok as they didn't tell you specifically how to show it, but i'm sure there was probably a 'better' way that also made the last part doable

    I'm actually quite disappointed with myself, I got the solution to Q2 in under half an hour and got all excited like I could be on to a really good score, then i just kept starting questions and not seeing them through. Poor question choice and lack of time management let me down I think.
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    (Original post by Zacken)
    This is most likely a very high 2 or a very low 1.


    Thank you Zacken That difference between a 2 and a 1 is gonna be a crucial one - from what you said it seems like a 78 which should definitely be a 1, but ofc we never know :/ (those are higher than I guessed so clearly I was biased or you're too kind hahah)

    Good luck with your cambridge offer too!
 
 
 
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