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

Mr M's OCR (not OCR MEI) Core 2 Answers May 2012 <strong><font Watch

    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    Community Assistant
    Mr M's OCR (not OCR MEI) Core 2 Answers May 2012


    1. (i) 243+810x+1080x^2+720x^3+240x^4+3  2x^5 (4 marks)

    (ii) 486+2160x^2+480x^4 (2 marks)


    2. (i) \frac{x^3}{3}-x^2+5x+k (3 marks)

    (ii) y=\frac{x^3}{3}-x^2+5x-4 (3 marks)


    3. (i) \frac{2\pi}{5} (1 mark)

    (ii) r = 15 (2 marks)

    (iii) 34.4 (3 marks)


    4. x = 48.6, 131, 90 degs (6 marks)


    5. (a) (i) u_2 =\frac{1}{2} and u_3 = 4 (2 marks)

    (ii) Cycles periodically between 4 and 1/2 (1 mark)

    (b) a = -2 and d = 2.5 (5 marks)


    6. (i) Show trapezium rule (3 mark)

    (ii) Sketch graph showing trapeziums under the curve (2 marks)

    (iii) \frac{208}{3} (4 marks)


    7. (a) (i) \frac{5 \sqrt{29}}{29} (2 marks)

    (ii) \frac{-2\sqrt{10}}{7} (3 marks)

    (b) \frac{3\sqrt{3}}{8} (3 marks)


    8. (i) Show a = -4 and obtain b = 3 (6 marks)

    (ii) f(x)=(x-1)(x-2)(x+3)

    g(x) also has (x+3) as a common factor (5 marks)


    9. (a) (i) Show fourth term (3 marks)

    (ii) x=\frac{4}{3} (2 marks)

    (b) (i) \frac{1}{2}&lt;y&lt;2 (2 marks)

    (ii) y=\frac{2}{3} (5 marks)
    Offline

    2
    ReputationRep:
    Thank you. I think I lost about 10 marks. Still, I've got M1, C3, C4 left.
    Offline

    0
    ReputationRep:
    Thank you very much looks like I've dropped one mark!
    Offline

    0
    ReputationRep:
    Thanks a lot! Reckon I'll just scrape an A fingers crossed! I stupidly put 0.67 rather than 2/3 for the last question. Anyone reckon I'll get the mark?
    Offline

    0
    ReputationRep:
    (Original post by Mr M)
    Mr M's OCR (not OCR MEI) Core 2 Answers May 2012


    1. (i) 243+810x+1080x^2+720x^3+240x^4+3  2x^5 (4 marks)

    (ii) 486+2160x^2+480x^4 (2 marks)


    2. (i) \frac{x^3}{3}-x^2+5x+k (3 marks)

    (ii) y=\frac{x^3}{3}-x^2+5x-4 (3 marks)


    3. (i) \frac{2\pi}{5} (1 mark)

    (ii) r = 15 (2 marks)

    (iii) 34.4 (3 marks)


    4. x = 48.6, 131, 90 degs (6 marks)


    5. (a) (i) u_2 =\frac{1}{2} and u_3 = 4 (2 marks)

    (ii) Cycles periodically between 4 and 1/2 (1 mark)

    (b) a = -2 and d = 2.5 (5 marks)


    6. (i) Show trapezium rule (3 mark)

    (ii) Sketch graph showing trapeziums under the curve (2 marks)

    (iii) \frac{208}{3} (4 marks)


    7. (a) (i) \frac{5 \sqrt{29}}{29} (2 marks)

    (ii) \frac{-2\sqrt{10}}{7} (3 marks)

    (b) \frac{3\sqrt{3}}{8} (3 marks)


    8. (i) Show a = -4 and obtain b = 3 (6 marks)

    (ii) f(x)=(x-1)(x-2)(x+3)

    g(x) also has (x+3) as a common factor (5 marks)


    9. (a) (i) Show fourth term (3 marks)

    (ii) x=\frac{4}{3} (2 marks)

    (b) (i) \frac{1}{2}&lt;y&lt;2 (2 marks)

    (ii) y=\frac{2}{3} (5 marks)
    MR M, if i obtained the wrong radius... I put 15/sqrt pi
    does that mean I lose 1 mark from the first question and 2 marks from the next question?
    or do I loose all 5 marks as I used 15/sqrt pi as r?
    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    Community Assistant
    (Original post by BenjaminKyle)
    for the tanx=2/5 where x is acute (just take x as alpha)

    would a viable answer be this :

    sinx/cosx = 2/5

    (2cosx)/5=sinx

    thus cosx = (5sinx)/2
    or is that not an EXACT answer? When i input the value for 'x' both sides are equal.

    I went on a similar trail of thought for the second question (the obtuse angle), yet with more complex rearranging, but still both sides equaled when i took the obtuse value of beta.

    would this recieve any marks at all lol? It's annoying as I did the correct method with the triangle but gave up on it for some reason
    No that isn't worth any marks I'm afraid.
    Offline

    0
    ReputationRep:
    what was the last question about?
    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    Community Assistant
    (Original post by JASApplications)
    Thanks a lot! Reckon I'll just scrape an A fingers crossed! I stupidly put 0.67 rather than 2/3 for the last question. Anyone reckon I'll get the mark?
    drop 1 mark - sorry!
    Offline

    0
    ReputationRep:
    (Original post by Seanyboy57)
    Thank you very much looks like I've dropped one mark!
    Hey do you remember what the last question was by any chance, I mean the last part of the last question one that was worth 5 marks.
    Offline

    0
    ReputationRep:
    (Original post by Mr M)
    Mr M's OCR (not OCR MEI) Core 2 Answers May 2012


    1. (i) 243+810x+1080x^2+720x^3+240x^4+3  2x^5 (4 marks)

    (ii) 486+2160x^2+480x^4 (2 marks)


    2. (i) \frac{x^3}{3}-x^2+5x+k (3 marks)

    (ii) y=\frac{x^3}{3}-x^2+5x-4 (3 marks)


    3. (i) \frac{2\pi}{5} (1 mark)

    (ii) r = 15 (2 marks)

    (iii) 34.4 (3 marks)


    4. x = 48.6, 131, 90 degs (6 marks)


    5. (a) (i) u_2 =\frac{1}{2} and u_3 = 4 (2 marks)

    (ii) Cycles periodically between 4 and 1/2 (1 mark)

    (b) a = -2 and d = 2.5 (5 marks)


    6. (i) Show trapezium rule (3 mark)

    (ii) Sketch graph showing trapeziums under the curve (2 marks)

    (iii) \frac{208}{3} (4 marks)


    7. (a) (i) \frac{5 \sqrt{29}}{29} (2 marks)

    (ii) \frac{-2\sqrt{10}}{7} (3 marks)

    (b) \frac{3\sqrt{3}}{8} (3 marks)


    8. (i) Show a = -4 and obtain b = 3 (6 marks)

    (ii) f(x)=(x-1)(x-2)(x+3)

    g(x) also has (x+3) as a common factor (5 marks)


    9. (a) (i) Show fourth term (3 marks)

    (ii) x=\frac{4}{3} (2 marks)

    (b) (i) \frac{1}{2}&lt;y&lt;2 (2 marks)

    (ii) y=\frac{2}{3} (5 marks)
    Also MR M, what would 66/72 be in UMS marks? Just a rough guesstimate?
    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    Community Assistant
    (Original post by J DOT A)
    MR M, if i obtained the wrong radius... I put 15/sqrt pi
    does that mean I lose 1 mark from the first question and 2 marks from the next question?
    or do I loose all 5 marks as I used 15/sqrt pi as r?
    You might lose more than 1 mark for the first bit. Just drop 1 mark for the second bit if your method was right.
    Offline

    0
    ReputationRep:
    Mr.M, I put "repeating" instead of periodic, would I get the mark?
    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    Community Assistant
    (Original post by IShouldBeRevising_)
    Hey do you remember what the last question was by any chance, I mean the last part of the last question one that was worth 5 marks.
    Find the exact value of y for which the sum to infinity of the G.P. is 3
    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    Community Assistant
    (Original post by J DOT A)
    Also MR M, what would 66/72 be in UMS marks? Just a rough guesstimate?
    Really don't want to guess
    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    Community Assistant
    (Original post by J.C)
    Mr.M, I put "repeating" instead of periodic, would I get the mark?
    yes
    Offline

    0
    ReputationRep:
    i said the odd ones are 4 and the even ones are 1/2 so it fluctuates between 4 and 1/2. i also for question seven rounded it to 3 s.f did they want exact values??
    Offline

    0
    ReputationRep:
    if you could let us know where each mark is obtained in 7ai) and 7aii), it would be greatly appreciated by many. i'd also like to thank you for your efforts, it's very helpful to see where you went wrong in an exam within such short notice to try and not make similarly made mistakes in subsequent and very close exams.
    Offline

    0
    ReputationRep:
    (Original post by Mr M)
    yes
    So hopefully 69/72 for me then. Unless there are some marks for 7.a)ii) I could get. For using triangles and working out the acute, would there be anything? (being really hopefull here as I know how its done and it's nothing like that)
    Offline

    0
    ReputationRep:
    I hadn't noticed for question 7 that it asked for exact answers and gave decimals (to 3 s.f.), will I lose a mark for each? Or am I looking at losing all 5 marks? :'(


    Thanks
    Offline

    0
    ReputationRep:
    (Original post by Mr M)
    Find the exact value of y for which the sum to infinity of the G.P. is 3
    A+n was log base 2 27

    What was r ?

    I'm really annoyed I messed up in this question, I want to see if I can do it now
 
 
 
  • 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 rather give up salt or pepper?
  • 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

    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.