Turn on thread page Beta
    Offline

    2
    ReputationRep:
    (Original post by iMacJack)
    My neck hurts now!
    Sorry, trying to get the best shot, my bad.
    Offline

    22
    ReputationRep:
    (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.
    Offline

    3
    ReputationRep:
    (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)
    Offline

    2
    ReputationRep:
    (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
    Attached Images
     
    Offline

    4
    ReputationRep:
    (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.
    • Community Assistant
    Offline

    19
    ReputationRep:
    Community Assistant
    (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
    • Community Assistant
    Offline

    19
    ReputationRep:
    Community Assistant
    gonna finish working in 10 mins - time for the sri lanka cricket highlights
    Offline

    16
    ReputationRep:
    (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
    Offline

    15
    ReputationRep:
    When would I use/not use the proof method where u make f(k) = ()m ?
    Offline

    4
    ReputationRep:
    (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.
    • Community Assistant
    Offline

    18
    ReputationRep:
    Community Assistant
    (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.
    Offline

    13
    ReputationRep:
    (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
    Offline

    4
    ReputationRep:
    (Original post by AAls)
    When would I use/not use the proof method where u make f(k) = ()m ?
    proving something is divisible.
    Offline

    4
    ReputationRep:
    (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?
    Offline

    15
    ReputationRep:
    (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)?
    Offline

    13
    ReputationRep:
    (Original post by thelegend99)
    Have you got the full paper with mark scheme?
    I uploaded it. It got taken down. :/


    Posted from TSR Mobile
    Offline

    4
    ReputationRep:
    (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.
    Offline

    16
    ReputationRep:
    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
Views: 149
Size:  119.0 KB


    Posted from TSR Mobile
    Offline

    3
    ReputationRep:
    Can someone please check my working her:

    2x2x7 = 4x7 = 28

    Rep me if im right

    Thanks!!!!

    Bit worried about FP1
    Offline

    4
    ReputationRep:
    Does anyone know how to do Question 3 from FP1 Practice Paper C? Never seen before. Attached the paper
    Attached Images
  1. File Type: pdf FP1 practice paper C.pdf (33.9 KB, 50 views)
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: August 18, 2016

1,888

students online now

800,000+

Exam discussions

Find your exam discussion here

Poll
Should universities take a stronger line on drugs?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.