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

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  1. Ursin's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    Mr M,
    If I wrote the three values for question 4, but also 270, will I lose marks? If so how many? Thanks
  2. J.C's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    If I'm remembering all my answers right I should hopefully get 69/72. Was aiming for full marks but that damn obtuse angle question got me. Still good though.
  3. Millyshyn's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    My answers to question 7i and ii were divided by roots and I didn't think to rationalise them (otherwise answer correct), will it be ok?
  4. Mr M's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    (Original post by whitenosugar)
    Hi Mr M,

    For question 4, I used the right trig identities and got to 4sin^2x - 7sinx + 3 = 0 (not sure if I've remembered it correctly) but then I must've stupidly factorised it wrong and ended up with x= 30, 150.

    Do you think I'd get any of the 6 marks, seeing as my method was correct(ish)?

    Thankyou!
    You will get 2 marks.

    Bet you factorised it as (2 sinx - 1)(2 sin x -3) instead of (4 sin x - 3)(sin x -1)
  5. Mr M's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    (Original post by jodiedoodles)
    Thanks! Sorry to be a pain but do you have any idea how many raw marks around 75-80 UMS would need?
    Not really
  6. Snakefingers13's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    Re the periodic sequence, is saying that it oscillates between 4 and 1/2 also a valid answer?
  7. Mr M's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    (Original post by Janet9311)
    Hello Mr M,
    If I wrote 2sqrt10/7 for 7(ii), how many marks will I lost?
    drop 1
  8. KS8's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    Looks like I've done well but I didn't have time to go back and check everything. :facepalm2:

    Mr. M, on the question where you had to work out the segment, I got the correct answer but used the formula

    Area = (1/2)r^2(theta - sin(theta))

    Would I be ok for the marks here or are some marks awarded for showing that you can apply the area of a triangle formula and subtract that from the sector area? Whereas I just used the above formula to jump straight to the answer.
  9. Ursin's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    (Original post by Mr M)
    It isn't a solution - I don't know where your 270 came from?
    I stupidly thoght 90 add another 90 for the reflection...I don't know why I thought that.
  10. Mr M's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    (Original post by propertimbo)
    On the last question I got y to equal -1 would I get any method marks or none at all?

    This was posted from The Student Room's Android App on my HTC One X
    I don't know what you did so can't say but it doesn't look promising.
  11. hannah1994's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    I stupidly didn't read the pi after the 45 in question 3, but did everything else right. How many marks will i lose? Also if you left the answer as 5/root 29 for 7ai will you lose any marks seeing as it was just a 2 mark question? Also for the 2nd part I got the right answer (apart from minus sign), but again didn't simplify my surd. do you reckon I'll have lost any marks?
  12. saj1994's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    HI Mr M,

    On Q2ii) i got the wrong value for c instead of getting -4 i got -22, i did all the working out correct but i think its a calculation error, how many marks would i get for this?

    On Q5aii) I put the sequence repeats itself every 2 terms, would i get a mark for this.

    On Q7 I used the SOH CAH TOA rule and the pythagoras rule to get different answers would get any marks for this.
  13. Mr M's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    (Original post by Millyshyn)
    My answers to question 7i and ii were divided by roots and I didn't think to rationalise them (otherwise answer correct), will it be ok?
    yes that's fine
  14. IShouldBeRevising_'s Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    (Original post by Mr M)
    I don't know what you did so can't say but it doesn't look promising.
    Mr M last question please, Do you think this papers was hard relative to the other c2 papers, also what raw mark do you think will be an A, Thanks
  15. Mr M's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    (Original post by KS8)
    Looks like I've done well but I didn't have time to go back and check everything. :facepalm2:

    Mr. M, on the question where you had to work out the segment, I got the correct answer but used the formula

    Area = (1/2)r^2(theta - sin(theta))

    Would I be ok for the marks here or are some marks awarded for showing that you can apply the area of a triangle formula and subtract that from the sector area? Whereas I just used the above formula to jump straight to the answer.
    I did the same as you - it's fine
  16. Mr M's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    (Original post by Ursin)
    Mr M,
    If I wrote the three values for question 4, but also 270, will I lose marks? If so how many? Thanks
    drop 1 mark
  17. Oli-Ol's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    Thank you so much Mr M! This is incredibly helpful.


    So cross about question 7 >





    Edit: Ok usually I don't mind negs but really? What did I do for that?
    Last edited by Oli-Ol; 18-05-2012 at 20:42.
  18. Mr M's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    (Original post by Snakefingers13)
    Re the periodic sequence, is saying that it oscillates between 4 and 1/2 also a valid answer?
    yes
  19. whitenosugar's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    (Original post by Mr M)
    You will get 2 marks.

    Bet you factorised it as (2 sinx - 1)(2 sin x -3) instead of (4 sin x - 3)(sin x -1)
    Yeah I did you're right! really kicking myself now, but thankyou!
  20. J DOT A's Avatar
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    Re: Mr M's OCR (not OCR MEI) Core 2 Answers May 2012
    (Original post by Mr M)
    drop 1
    Yeah MR M, I used the formula for segment...A=0.5r^2(theta-sintheta) with a value of 15/sqrt pi, would I get 2 method marks out of 3 for using the formula?
    It's just that my r value was incorrect.

    Also, You said I might loose 2 marks for getting incorrect r value..but wouldn't there be on for method?

    Finally, for 7ii I got that answer but postive, I used a triangle and did the acute angle..how many marks would I drop?
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