Hey there! Sign in to join this conversationNew here? Join for free
    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    Mr M's OCR (not OCR MEI) Core 1 Answers May 2013


    1. (i) 12 \sqrt 5 (2 marks)

    (ii) 4 \sqrt 5 (1 mark)

    (iii) 5 \sqrt 5 (1 mark)


    2. x=\frac{1}{2} or x=-1 (5 marks)


    3. (i) f'(x)=2-\frac{12}{x^3} (3 marks)

    (ii) f''(x)=\frac{36}{x^4} (2 marks)


    4. (i) 3(x+\frac{3}{2})^2+\frac{13}{4} (3 marks)

    (ii) (-\frac{3}{2}, \frac{13}{4}) (3 marks)

    (iii) -39 (2 marks)


    5. (i) Correct sketch (2 marks)

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

    (iii) Stretch scale factor \frac{1}{2} parallel to y axis (2 marks)


    6. (i) Centre (0, -4) and radius 2 \sqrt{10} (3 marks)

    (ii) (-2, -10) (2 marks)


    7. (i) x<-\frac{1}{8} (2 marks)

    (ii) 0 \leq x \leq 5 (5 marks)


    8. 6x+2y-1=0 (7 marks)


    9. (i) Correct sketch with intersections at (-1.5, 0) and (2, 0) and (0, -6) (5 marks)

    (ii) x \leq \frac{1}{4} OR x < \frac{1}{4} (either will be marked correct) (3 marks)

    (iii) 4.5 (4 marks)


    10. (i) k=-5 (7 marks)

    (ii) Minimum (2 marks)

    (iii) (-2, -27) (5 marks)


    I'll be around to answer questions shortly.
    Offline

    1
    ReputationRep:
    (Original post by Mr M)
    Mr M's OCR (not OCR MEI) Core 1 Answers May 2013


    1. (i) 12 \sqrt 5 (2 marks)

    (ii) 4 \sqrt 5 (1 mark)

    (iii) 5 \sqrt 5 (1 mark)


    2. x=\frac{1}{2} or x=-1 (5 marks)


    3. (i) f'(x)=2-\frac{12}{x^3} (3 marks)

    (ii) f''(x)=\frac{36}{x^4} (2 marks)


    4. (i) 3(x+\frac{3}{2})^2+\frac{13}{4} (3 marks)

    (ii) (-\frac{3}{2}, \frac{13}{4}) (3 marks)

    (iii) -39 (2 marks)


    5. (i) Correct sketch (2 marks)

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

    (iii) Stretch scale factor \frac{1}{2} parallel to y axis (2 marks)


    6. (i) Centre (0, -4) and radius 2 \sqrt{10} (3 marks)

    (ii) (-2, -10) (2 marks)


    7. (i) x<\frac{1}{8} (2 marks)

    (ii) 0 \leq x \leq 5 (5 marks)


    8. 6x+2y-1=0 (7 marks)


    9. (i) Correct sketch with intersections at (-1.5, 0) and (2, 0) (5 marks)

    (ii) x \leq \frac{1}{4} OR x < \frac{1}{4} (either will be marked correct) (3 marks)

    (iii) 4.5 (4 marks)


    10. (i) k=-5 (7 marks)

    (ii) Minimum (2 marks)

    (iii) (-2, -27) (5 marks)


    I'll be around to answer questions shortly.
    Mr M,

    I accidentally put k=5 rather than -5 with all the correct working. This meant that i got the wrong quadratic for part 10.iii. however i did the working correctly, equating the differentiated 9x-9 to my quadratic i got from differentiating the cubic in part i, but it turned out to be an unsolvable quadratic due to my incorrect value of k. How many marks would i probably lose? :/
    Thanks
    Offline

    18
    ReputationRep:
    (Original post by Mr M)
    Mr M's OCR (not OCR MEI) Core 1 Answers May 2013


    1. (i) 12 \sqrt 5 (2 marks)

    (ii) 4 \sqrt 5 (1 mark)

    (iii) 5 \sqrt 5 (1 mark)


    2. x=\frac{1}{2} or x=-1 (5 marks)


    3. (i) f'(x)=2-\frac{12}{x^3} (3 marks)

    (ii) f''(x)=\frac{36}{x^4} (2 marks)


    4. (i) 3(x+\frac{3}{2})^2+\frac{13}{4} (3 marks)

    (ii) (-\frac{3}{2}, \frac{13}{4}) (3 marks)

    (iii) -39 (2 marks)


    5. (i) Correct sketch (2 marks)

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

    (iii) Stretch scale factor \frac{1}{2} parallel to y axis (2 marks)


    6. (i) Centre (0, -4) and radius 2 \sqrt{10} (3 marks)

    (ii) (-2, -10) (2 marks)


    7. (i) x<\frac{1}{8} (2 marks)

    (ii) 0 \leq x \leq 5 (5 marks)


    8. 6x+2y-1=0 (7 marks)


    9. (i) Correct sketch with intersections at (-1.5, 0) and (2, 0) (5 marks)

    (ii) x \leq \frac{1}{4} OR x < \frac{1}{4} (either will be marked correct) (3 marks)

    (iii) 4.5 (4 marks)


    10. (i) k=-5 (7 marks)

    (ii) Minimum (2 marks)

    (iii) (-2, -27) (5 marks)


    I'll be around to answer questions shortly.
    shouldn't 7i be x<-1/8
    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    (Original post by Majeue)
    Mr M,

    I accidentally put k=5 rather than -5 with all the correct working. This meant that i got the wrong quadratic for part 10.iii. however i did the working correctly, equating the differentiated 9x-9 to my quadratic i got from differentiating the cubic in part i, but it came to be an unsolvable quadratic. How many marks would i probably lose? :/
    Thanks
    Lose 1 mark in part (i) and 1 or 2 in part (iii).
    Offline

    0
    ReputationRep:
    (Original post by Mr M)
    Mr M's OCR (not OCR MEI) Core 1 Answers May 2013

    9. (i) Correct sketch with intersections at (-1.5, 0) and (2, 0) (5 marks)
    and (0,-6) was needed for the y axis intercept ?
    Offline

    0
    ReputationRep:
    surely 7i is -1/8
    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    (Original post by a10)
    shouldn't 7i be x<-1/8
    Yes sorry typo. I'll fix it.
    Offline

    0
    ReputationRep:
    what will grade boundaries be like?
    Offline

    14
    ReputationRep:
    (Original post by Mr M)
    Mr M's OCR (not OCR MEI) Core 1 Answers May 2013


    1. (i) 12 \sqrt 5 (2 marks)

    (ii) 4 \sqrt 5 (1 mark)

    (iii) 5 \sqrt 5 (1 mark)


    2. x=\frac{1}{2} or x=-1 (5 marks)


    3. (i) f'(x)=2-\frac{12}{x^3} (3 marks)

    (ii) f''(x)=\frac{36}{x^4} (2 marks)


    4. (i) 3(x+\frac{3}{2})^2+\frac{13}{4} (3 marks)

    (ii) (-\frac{3}{2}, \frac{13}{4}) (3 marks)

    (iii) -39 (2 marks)


    5. (i) Correct sketch (2 marks)

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

    (iii) Stretch scale factor \frac{1}{2} parallel to y axis (2 marks)


    6. (i) Centre (0, -4) and radius 2 \sqrt{10} (3 marks)

    (ii) (-2, -10) (2 marks)


    7. (i) x&lt;\frac{1}{8} (2 marks)

    (ii) 0 \leq x \leq 5 (5 marks)


    8. 6x+2y-1=0 (7 marks)


    9. (i) Correct sketch with intersections at (-1.5, 0) and (2, 0) (5 marks)

    (ii) x \leq \frac{1}{4} OR x &lt; \frac{1}{4} (either will be marked correct) (3 marks)

    (iii) 4.5 (4 marks)


    10. (i) k=-5 (7 marks)

    (ii) Minimum (2 marks)

    (iii) (-2, -27) (5 marks)


    I'll be around to answer questions shortly.
    Ohh! Looks like I only dropped one or two marks.

    How many marks would you drop if put two answers for the last one. I put -2,-27 and -9,0
    I know the second one is incorrect since there's only one one tangent.
    Offline

    0
    ReputationRep:
    How many marks will you get for finding the two coordinates on the last question but doing no further working
    Offline

    0
    ReputationRep:
    Hi, if for question 9(i) i got the (1.5,0) and (-2,0) instead, how many marks would i drop? thanks

    also for part 9(iii) i got the correct answer but left it as sqrt(81/4).. do i lose marks for this?
    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    (Original post by queketth)
    and (0,-6) was needed for the y axis intercept ?
    Thanks. I actually missed that off my working. Will amend.
    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    (Original post by daisyrchds)
    Hi, if for question 9(i) i got the (1.5,0) and (-2,0) instead, how many marks would i drop? thanks
    Probably 2.
    Offline

    9
    ReputationRep:
    (Original post by Mr M)
    Mr M's OCR (not OCR MEI) Core 1 Answers May 2013
    9. (i) Correct sketch with intersections at (-1.5, 0) and (2, 0) and (0, -6) (5 marks)
    Does this means you won't be penalised for not labelling the intersection with the Y axis?

    EDIT: Nevermind, you sneakily edited while I quoted you. I labelled in anyway though so
    Offline

    0
    ReputationRep:
    M1 please
    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    (Original post by geekD96)
    what will grade boundaries be like?
    No idea. It seemed pretty easy to me as I did it in 10 minutes but I used a computer for most of it which is major league cheating.

    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    (Original post by Khomy2011)
    M1 please
    Pardon?
    Offline

    0
    ReputationRep:
    also for part 9(iii) i got the correct answer but left it as sqrt(81/4).. do i lose marks for this?
    Offline

    0
    ReputationRep:
    (Original post by Mr M)
    Mr M's OCR (not OCR MEI) Core 1 Answers May 2013


    1. (i) 12 \sqrt 5 (2 marks)

    (ii) 4 \sqrt 5 (1 mark)

    (iii) 5 \sqrt 5 (1 mark)


    2. x=\frac{1}{2} or x=-1 (5 marks)


    3. (i) f'(x)=2-\frac{12}{x^3} (3 marks)

    (ii) f''(x)=\frac{36}{x^4} (2 marks)


    4. (i) 3(x+\frac{3}{2})^2+\frac{13}{4} (3 marks)

    (ii) (-\frac{3}{2}, \frac{13}{4}) (3 marks)

    (iii) -39 (2 marks)


    5. (i) Correct sketch (2 marks)

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

    (iii) Stretch scale factor \frac{1}{2} parallel to y axis (2 marks)


    6. (i) Centre (0, -4) and radius 2 \sqrt{10} (3 marks)

    (ii) (-2, -10) (2 marks)


    7. (i) x&lt;-\frac{1}{8} (2 marks)

    (ii) 0 \leq x \leq 5 (5 marks)


    8. 6x+2y-1=0 (7 marks)


    9. (i) Correct sketch with intersections at (-1.5, 0) and (2, 0) and (0, -6) (5 marks)

    (ii) x \leq \frac{1}{4} OR x &lt; \frac{1}{4} (either will be marked correct) (3 marks)

    (iii) 4.5 (4 marks)


    10. (i) k=-5 (7 marks)

    (ii) Minimum (2 marks)

    (iii) (-2, -27) (5 marks)


    I'll be around to answer questions shortly.

    For question 2, i put 8^-1/3
    Will I still get the mark? I don't know why I wrote it so weirdly, but it is technically still right isn't it?
    • Community Assistant
    • Thread Starter
    Offline

    20
    ReputationRep:
    (Original post by daisyrchds)
    for part 9(iii) i got the correct answer but left it as sqrt(81/4).. do i lose marks for this?
    No that's fine.
 
 
 
  • 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
    Are unpaid trial work shifts fair?
  • 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.