Hey there! Sign in to join this conversationNew here? Join for free
    Offline

    3
    ReputationRep:
    Are the locus quetions within the spec- they come up quite often in the practice qs?
    Offline

    3
    ReputationRep:
    (Original post by thesmallman)
    Are the locus quetions within the spec- they come up quite often in the practice qs?
    They are not in the FP1 specification. They are only in the FP3 specification.

    For FP1 coordinate systems, you need to be able to:
    • Use Cartesian and parametric equations for parabola & rectangular hyperbola
    • Use the focus-directrix property of the parabola
    • Find tangents and normals to the curves
    • + anything in C1/C2 Coordinate Systems
    Offline

    10
    ReputationRep:
    With divisibility proof questions, can you use the method where you assume f(k) is divisible by 5 and so have f(k)=5m (rearranging it and substituting into f(k+1), and still get full marks? It's not a popular method like the f(k+1)-f(k) method but I often find it easier, don't want to risk not getting full marks though.
    Offline

    3
    ReputationRep:
    (Original post by Windowswind123)
    For proof by induction divisibility questions.... Not sure how to word it so I will give an example..
    Prove that 3^(2n+3) + 3n +2 is divisible by 9 (probably not true)
    Can you in your induction step go straight to :
    f(k+1) - 9f(k) = blah blah
    To cancel the 3^(2n+3) term or do you need to start with a coefficient of one?
    you would have to say f(k+1)=..... or f(k+1)-f(k)=....... and then end up making it f(k+1)
    Offline

    1
    ReputationRep:
    Is part c part of the spec because it's the only part of the question I can't do and I've never seen anything similar in a past paper. Also if it is how do you do it?

    Attached Images
     
    Offline

    3
    ReputationRep:
    (Original post by TheMoon)
    With divisibility proof questions, can you use the method where you assume f(k) is divisible by 5 and so have f(k)=5m (rearranging it and substituting into f(k+1), and still get full marks? It's not a popular method like the f(k+1)-f(k) method but I often find it easier, don't want to risk not getting full marks though.
    Haven't seen that method in mark schemes so i am not sure. Would go for f)k+1-f(k) as it is popular and usually gets you the six marks. Good luck
    Offline

    4
    ReputationRep:
    (Original post by veejn)
    Is part c part of the spec because it's the only part of the question I can't do and I've never seen anything similar in a past paper. Also if it is how do you do it?
    Haven't seen this ever before, I think that it's outside the spec. What one are you looking at?
    Offline

    3
    ReputationRep:
    (Original post by veejn)
    Is part c part of the spec because it's the only part of the question I can't do and I've never seen anything similar in a past paper. Also if it is how do you do it?

    if you don't mind me asking what paper is this from?
    Offline

    2
    ReputationRep:
    (Original post by anujsr)
    you would have to say f(k+1)=..... or f(k+1)-f(k)=....... and then end up making it f(k+1)
    Oh really
    I've always practiced by doing f(k+1) - xf(k) =
    Then adding the xf(k) at the end.
    And saying if f(k) is divisible, xf(k) is divisible and so true for n=k+1

    Maybe in the exam I'll try and do it both ways. They credit your highest scoring method right?
    Offline

    3
    ReputationRep:
    (Original post by Windowswind123)
    Oh really
    I've always practiced by doing f(k+1) - xf(k) =
    Then adding the xf(k) at the end.
    And saying if f(k) is divisible, xf(k) is divisible and so true for n=k+1

    Maybe in the exam I'll try and do it both ways. They credit your highest scoring method right?
    I use that method because i have seen it in almost all the mark schemes. I am not sure about your method but if thats the one you are comfortable with use it
    Offline

    10
    ReputationRep:
    (Original post by anujsr)
    Haven't seen that method in mark schemes so i am not sure. Would go for f)k+1-f(k) as it is popular and usually gets you the six marks. Good luck
    This is the method I'm talking about, I've seen it in the textbook so I thought it would be allowed:



    ^this was from the textbook "review 2" solutions.
    Offline

    3
    ReputationRep:
    (Original post by anujsr)
    I use that method because i have seen it in almost all the mark schemes. I am not sure about your method but if thats the one you are comfortable with use it
    It is basically the same thing only that you get the xf(k) on the right hand side rather than the left. that is f(k+1)-f(k)=8f(k)+8(30k+5) for example. then you move the f(k) to the right. You should be credited for your method if you end up with the correct proof. THe mark scheme gives many proofs. My advice would be check in other mark schemes as well. Good luck.
    Offline

    2
    ReputationRep:
    (Original post by anujsr)
    I use that method because i have seen it in almost all the mark schemes. I am not sure about your method but if thats the one you are comfortable with use it
    Phew, had a quick panic but then I saw my method is https://7cba9babeb0db0ff9468853e0b2d...%20Edexcel.pdf (question 9 method 3).
    Thanks for the help anyway
    Offline

    3
    ReputationRep:
    (Original post by TheMoon)
    This is the method I'm talking about, I've seen it in the textbook so I thought it would be allowed:



    ^this was from the textbook "review 2" solutions.
    Then its alright!
    Offline

    3
    ReputationRep:
    (Original post by veejn)
    Is part c part of the spec because it's the only part of the question I can't do and I've never seen anything similar in a past paper. Also if it is how do you do it?

    It's more FP3, than FP1. I wouldn't worry about it
    Offline

    1
    ReputationRep:
    (Original post by anujsr)
    if you don't mind me asking what paper is this from?
    It's from a revision sheet provided by my school
    Offline

    3
    ReputationRep:
    (Original post by Windowswind123)
    Phew, had a quick panic but then I saw my method is https://7cba9babeb0db0ff9468853e0b2d...%20Edexcel.pdf (question 9 method 3).
    Thanks for the help anyway

    Haha.. sorry about that. Hope the exam goes well. How long do you take to finish this paper though.
    Offline

    3
    ReputationRep:
    (Original post by veejn)
    It's from a revision sheet provided by my school
    It must be from the old specification then. haven't seen that in the text book though.
    Offline

    2
    ReputationRep:
    (Original post by anujsr)
    Haha.. sorry about that. Hope the exam goes well. How long do you take to finish this paper though.
    Usually around the hour mark.
    Offline

    1
    ReputationRep:
    (Original post by kingaaran)
    It's more FP3, than FP1. I wouldn't worry about it
    Ok thanks
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Would you like to hibernate through the winter months?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • 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

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