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    (Original post by iMacJack)
    My neck hurts now!
    Sorry, trying to get the best shot, my bad.
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    (Original post by iMacJack)
    Aha got ya.

    Also, you know in the F1 Jan 16 paper you sit, you see the question about the coordinates of where the normal intersects the parabola again (or something along those lines) and you have a dirty quadratic with like p^3 and p^4's and what not - how on earth do you use the quadratic formula successfully to work out the coordinates?? I'm so baffled!

    https://gyazo.com/98e0758d1498ec2a5addcd7bfc1f15ee

    Part B is what I'm on about
    Quadratic formula and simplify. You should find that you end up with -b \pm \sqrt{(f(p))^2} where f(p) is some random function of p.

    I lost two marks for miscopying my answer from one page to the next on this question.
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    (Original post by Coreling)
    Can anyone explain where the 18p^2 goes in this question? seems to disappear? From the June15 paper question 8 (a).
    9 is a factor of all the values in the root sign. so it is taken out and sqr rooted.

    i.e sqrrt(9p^4 + 18p^2 + 9) = sqrrt(9) * sqrrt(p^4 + 2p^2 + 1)

    this is 3 * sqrrt(p^4 + 2p^2 + 1)

    = 3(p^2 + 1)
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    (Original post by iMacJack)
    Any help with this proof by induction question please? Thanks!

    Zacken NotNotBatman kingaaran etc! Thank you!

    Question from CM PBI worksheet
    Dunno if the picture will work but is this method ok with mark schemes? Haven't seen it yet
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    (Original post by iMacJack)
    Any help with this proof by induction question please? Thanks!

    Zacken NotNotBatman kingaaran etc! Thank you!

    Question from CM PBI worksheet
    Basically means, prove that it's divisible by 3.
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    (Original post by iMacJack)
    Aha got ya.

    Also, you know in the F1 Jan 16 paper you sit, you see the question about the coordinates of where the normal intersects the parabola again (or something along those lines) and you have a dirty quadratic with like p^3 and p^4's and what not - how on earth do you use the quadratic formula successfully to work out the coordinates?? I'm so baffled!

    https://gyazo.com/98e0758d1498ec2a5addcd7bfc1f15ee

    Part B is what I'm on about
    got the expression and didn't realise that you could use the formula. Basically expand it and you end up with p^4 + p^2 +c so sub p^2 = x to get a normal expression and then use the formula
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    gonna finish working in 10 mins - time for the sri lanka cricket highlights
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    (Original post by thelegend99)
    Basically means, prove that it's divisible by 3.
    Yeah I know haha I was just unable to get the inductive step
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    When would I use/not use the proof method where u make f(k) = ()m ?
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    (Original post by iMacJack)
    Yeah I know haha I was just unable to get the inductive step
    Oh ok, have you got it now? I might give that one a try.
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    (Original post by iMacJack)
    Any help with this proof by induction question please? Thanks!

    Zacken NotNotBatman kingaaran etc! Thank you!

    Question from CM PBI worksheet
    When doing the f(k)-f(k+1), I find that's it's easier if you simplify the powers first, then when you subtract, group and rearrange, rather than having loads of brackets.

    When you get to that stage 'force in' some multiple of  f(k) , and then add/subtract to compensate and make it equal to your previous step. The multiple of f(k) should be so that the remaining bit is both divisible by 3.


    If you look at the worked solutions to the divisibility test on madasmaths, this shows, imo, the best way to do it.
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    (Original post by iMacJack)
    Aha got ya.

    Also, you know in the F1 Jan 16 paper you sit, you see the question about the coordinates of where the normal intersects the parabola again (or something along those lines) and you have a dirty quadratic with like p^3 and p^4's and what not - how on earth do you use the quadratic formula successfully to work out the coordinates?? I'm so baffled!

    https://gyazo.com/98e0758d1498ec2a5addcd7bfc1f15ee

    Part B is what I'm on about
    I'd factorise. You already know that y=c/p (or x =cp) is a solution, so you know that one of the brackets must be (py-c). Then you can use inspection to see what the other bracket has to be
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    (Original post by AAls)
    When would I use/not use the proof method where u make f(k) = ()m ?
    proving something is divisible.
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    (Original post by kingaaran)
    I'd factorise. You already know that y=c/p (or x =cp) is a solution, so you know that one of the brackets must be (py-c). Then you can use inspection to see what the other bracket has to be
    Have you got the full paper with mark scheme?
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    (Original post by thelegend99)
    proving something is divisible.
    Yes, but does it always work or would I have to use a different method like f(k+1) -f(k)?
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    (Original post by thelegend99)
    Have you got the full paper with mark scheme?
    I uploaded it. It got taken down. :/


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    (Original post by AAls)
    Yes, but does it always work or would I have to use a different method like f(k+1) -f(k)?
    I think that it would be better to use overall, but if you're comfortable with f(k+1) - f(k) method then use that. Don't change anything too late.
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    Like this Zacken/Aaran??
    Apologies for the mess but I rushed it because you know I'm trying to get it resolved quickly :P
    Zacken kingaaran
    Name:  ImageUploadedByStudent Room1463679237.941819.jpg
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Size:  119.0 KB


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    Can someone please check my working her:

    2x2x7 = 4x7 = 28

    Rep me if im right

    Thanks!!!!

    Bit worried about FP1
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    Does anyone know how to do Question 3 from FP1 Practice Paper C? Never seen before. Attached the paper
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  1. File Type: pdf FP1 practice paper C.pdf (33.9 KB, 43 views)
 
 
 
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