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

Mr M's OCR (not OCR MEI) Core 3 Answers June 2012

Announcements Posted on
    • Thread Starter
    • 327 followers
    Offline

    ReputationRep:
    Mr M's OCR (not OCR MEI) Core 3 Answers June 2012


    1. x<\frac{4}{3} and x>6 (5 marks)


    2. (i) Show 261 (3 marks)

    (ii) 361 (3 marks)


    3. (i) Show tan theta = 6 (3 marks)

    (ii) (a) \frac{5}{7} (2 marks)

    (b) -\frac{12}{35} (2 marks)


    4. (a) Show integral = 24 (4 marks)

    (b) \frac{e^2+8e-1}{2} (4 marks)


    5. (i) Show one real root (3 marks)

    (ii) (a) 3 and 4 (3 marks)

    (b) 3.24 (4 marks)


    6. (i) 12.17 (4 marks)

    (ii) 0.183 cubic metres per hour (3 marks)


    7. a = 4 and x = -0.5 (7 marks)


    8. (i) 5 \sin (\theta + 53.1301) (3 marks)

    (ii) (a) -64.7 degs and 138 degs (4 marks)

    (b) k = 8 and c = 3 (4 marks)


    9. (i) Show derivative (3 marks)

    (ii) \frac{\pi (3e^4 + 1)}{2} (6 marks)

    (iii) \frac{\pi (e^4 -1)}{2} (2 marks)
    • 29 followers
    Offline

    ReputationRep:
    thanks again!
    • 10 followers
    Online

    ReputationRep:
    Thanks
    • 0 followers
    Offline

    ReputationRep:
    Mr M, for question 9(ii) for some reason I differentiated ln(2y) instead of integrating (I was trying to integrate but I was just being retarded), and got my answer from there. Will I get a mark?

    EDIT: Btw thanks a lot for the solutions!
    • 29 followers
    Offline

    ReputationRep:
    Mr M 4(b) I accidently messed up when multiplying out the brackets but integrated the terms are everything fine - how many marks would I get for that?

    hope the after school meeting was...fun?
    • 0 followers
    Offline

    ReputationRep:
    Oh and would it be okay for 4(b) to give my answer as e(0.5e+4)-0.5? Thanks
    • Thread Starter
    • 327 followers
    Offline

    ReputationRep:
    (Original post by tahseen1995)
    Mr M, for question 9(ii) for some reason I differentiated ln(2y) instead of integrating (I was trying to integrate but I was just being retarded), and got my answer from there. Will I get a mark?

    EDIT: Btw thanks a lot for the solutions!
    I can't say from what you have told me - it doesn't sound hopeful!
    • 0 followers
    Offline

    ReputationRep:
    How many marks would I drop if I put 4/3 < x < 6 for q1
    , and for using g^1(x) instead of g(x) for the second part of 7?
    • Thread Starter
    • 327 followers
    Offline

    ReputationRep:
    (Original post by tahseen1995)
    Oh and would it be okay for 4(b) to give my answer as e(0.5e+4)-0.5? Thanks
    yes
    • 0 followers
    Offline

    ReputationRep:
    (Original post by Mr M)
    Mr M's OCR (not OCR MEI) Core 3 Answers June 2012
    Mr. M, for 9ii) (the 6 mark question), I did everything correctly up till the point where we had to calculate the lower bound. For some reason, because i'm a dog I differentiated rather than just plugging x=0 into f(x), hence I integrated with lower bound 1, instead of lower bound 1/2. All the steps in the integration were correct, but my final answer would be wrong since the lower limit I subbed in was wrong. How many marks would I lose in your opinion?
    • Thread Starter
    • 327 followers
    Offline

    ReputationRep:
    (Original post by Doctor.)
    Mr M 4(b) I accidently messed up when multiplying out the brackets but integrated the terms are everything fine - how many marks would I get for that?

    hope the after school meeting was...fun?
    It was mercifully brief. I did maths and pretended to listen.

    probably 2 marks
    • 0 followers
    Offline

    ReputationRep:
    I can't remember what I put for 4b, can anyone remember the question? Thanks.
    • Thread Starter
    • 327 followers
    Offline

    ReputationRep:
    (Original post by Tukazoar)
    How many marks would I drop if I put 4/3 < x < 6 for q1
    , and for using g^1(x) instead of g(x) for the second part of 7?
    drop 1 mark and drop 3 marks probably
    • 0 followers
    Offline

    ReputationRep:
    (Original post by Mr M)
    I can't say from what you have told me - it doesn't sound hopeful!
    What I meant is I correctly rearranged the equation to get pi times the integral of y=ln(2x) with limits of 1/2e^(4) and 1/2, but instead of using part (i) of question 9 to find the integral of ln(2x) I integrated ln(2x) to 1/x (I panicked due to lack of time) and went from there.

    I was wondering if would at least get a mark for correctly rearranging the equation and realising the the area of the shaded region rotated about the y axis would be the integral of ln(2x) within limits of 1/2e^(4) and 1/2 multiplied by pi.

    ...did I make sense?

    lol thank you
    • Thread Starter
    • 327 followers
    Offline

    ReputationRep:
    I'm off home now but will answer some more questions later (in about one hour).
    • 70 followers
    Offline

    ReputationRep:
    (Original post by Doctor.)
    Mr M 4(b) I accidently messed up when multiplying out the brackets but integrated the terms are everything fine - how many marks would I get for that?

    hope the after school meeting was...fun?

    (Original post by tahseen1995)
    Mr M, for question 9(ii) for some reason I differentiated ln(2y) instead of integrating (I was trying to integrate but I was just being retarded), and got my answer from there. Will I get a mark?

    EDIT: Btw thanks a lot for the solutions!
    Is this your actual teacher? Seems a bit weird but I suppose it's a good idea too.
    • 0 followers
    Offline

    ReputationRep:
    for 4b i put e^x2 and not 2x. hw much wud i lose and for the last i intergraded put the the y values. ie e^4 one in but got soma dfferent. like 2pi e^4. i also integrated the line and wrkd that out?
    • 29 followers
    Offline

    ReputationRep:
    (Original post by Junaid96)
    Is this your actual teacher? Seems a bit weird but I suppose it's a good idea too.
    Maybe :ninja:

    Just kidding, nope but I do casually stalk Mr M (Only on TSR lol) would be so weird if someone did that in real life :lol:
    • 1 follower
    Offline

    ReputationRep:
    How many marks would I lose for getting

    k = 3/5
    c = 40

    Because I read the question as 37 not MINUS 37!
    • 0 followers
    Offline

    ReputationRep:
    (Original post by Mr M)
    Mr M's OCR (not OCR MEI) Core 3 Answers June 2012

    Thanks. Just two questions.

    On question 9iii) if I used my answer from question 9ii) to calculate the volume (but followed the correct method) would I get any of the 2 marks?

    Also, on question 9ii) I got an incorrect answer as when I substituted in the limits I rewrote ln(e^4) as e^4 instead of 4. However, I applied the limits correctly to the other variables. (And applied the correct method throughout) How many marks out of the 6 is this likely to have costed me?

    Thanks a lot

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?

    this is what you'll be called on TSR

  2. this can't be left blank
    this email is already registered. Forgotten your password?

    never shared and never spammed

  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. By joining you agree to our Ts and Cs, privacy policy and site rules

  2. Slide the button to the right to create your account

    Slide to join now Processing…

Updated: August 29, 2012
New on TSR

Student crowdfunds degree

Graduate raises £26,000 online for Masters course

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