OCR (Not MEI) C2 May 2013 (17.5.13) UO Markscheme

I think I lost 10 marks +/-1 mark will this be an A? PLEASE PUT ME OUT OF MY MISERY! (roughly around 86%)

Using the grade boundaries for June 2012 (which was also a relatively easy paper) 57 maybe for an A. (it's usually in the 50's to get an A)

Is that not really low??? The grade boundaries for easy papers have been up to 65 aka Jan 09?

Reply 62

RooRoo1

10

Original post by CDL

Dont mean to be disrespectful to anyone's previous posts but I think a lot of people are mistaken on the grade boundaries for this paper. I am myself quite an able mathematician, scoring 96UMS on Core 1, and i did struggle with some aspects of the paper, especially 8ii. bearing in mind that most of the people who post on here are ALSO very able, i think we're forgetting that this was actually quite a difficult paper and will undoubtedly catch out the 'less able' candidates that took it, so my money is on 55-57 for an A grade :smile:

Thanks for pointing this out. I'm not particularly gifted with maths, and my teacher got really ill so we've basically taught ourselves most of the c2 & s1 stuff. I didn't find the paper that easy, I think I got around 45-52 marks (I can't remember some of the answers I put). So just wanted to say thanks for putting it out there that not everyone found it easy!

Reply 63

tgtips372

Hate to point this out, but I think the table of grade boundaries that Good@Math posted is for another specification :frown:

Reply 64

tgtips372

Does anyone know where we can find a table for previous grade boundaries for ease of use?

Reply 65

joostan

13

Original post by tgtips372

Does anyone know where we can find a table for previous grade boundaries for ease of use?

Can't find a table with them all in a list but here's the past 3. :smile:

Jan 2013
June 2012
Jan 2012

Reply 66

Good@Math

Original post by tgtips372

Hate to point this out, but I think the table of grade boundaries that Good@Math posted is for another specification :frown:

You're right, sorry.

------------A--B--C--D--E
Jan 13 - 54 47 40 34 28
Jun 13 - 57 51 45 39 33
Jan 12 - 60 53 46 40 34
Jun 11 - 59 52 46 40 34
Jan 11 - 60 53 46 39 33
Jun 10 - 57 51 45 40 35

Reply 67

Whyllee

Original post by RooRoo1

Thanks for pointing this out. I'm not particularly gifted with maths, and my teacher got really ill so we've basically taught ourselves most of the c2 & s1 stuff. I didn't find the paper that easy, I think I got around 45-52 marks (I can't remember some of the answers I put). So just wanted to say thanks for putting it out there that not everyone found it easy!

If it's 57 I'll sob with happiness (I have all my fingers and my toes and my arms and my legs crossed)

Reply 68

joostan

13

For the sake of completion:
7)i) Show that worked solution.

I = \displaystyle\int^4_1 x^{\frac{3}{2}} - 1 \ dx = \left[\dfrac{2}{5}x^{\frac{5}{2}} - x \right]^4_1[br]\Rightarrow I = \left(\dfrac{2}{5}(4^{\frac{5}{2}}) - 4\right) - \left(\dfrac{2}{5}(1^{\frac{5}{2}}) - 1\right)[br]\Rightarrow I = \dfrac{64}{5}-4+\dfrac{3}{5} = \dfrac{67-20}{5} = \dfrac{47}{5} = 9\frac{2}{5}

Reply 69

geekD96

7

Original post by Good@Math

1. 6.39 [4]
2i) 106, 254 [3]
2ii) 71.6, 252 [3]
3i) 64+960x+6000x^2 [4]
3ii) c=-11 [3]
4a) (5/4)x^4-3x^2+x+c [3]
4bi) -12x^-2+c [2]
4bii) a=+2 [3]
5i) 62.2 [4]
5ii) 34 [4]
6i) 963 [3]
6ii) 17 [6]
7i) show that [4]
7ii) 37/30 [5]
8ia) (0,1) [1]
8ib) (0,4) [1]
8ic) a>1 0<b<1 [2]
8ii) show that [5]
9i) 15 [2]
9ii) (2x+1)(2x-3)(x+1) [6]
9iii) 2/3pi, pi, 4/3pi [4]

THANKS AND how on earth did u manage to get the paper?!:O

Reply 70

HayyanN

Can someone please explain how they did 7 (ii)

Reply 71

Whyllee

Okay for 9ii) I got wrote (2x-3)(x+1) without the previous answer but then I wrote so x= -1/2 +2/3 or -1 will I lose a mark for having not written (2x+1)(2X-3)(X+1) ???

Reply 72

audi_turbo

16

Original post by HayyanN

Can someone please explain how they did 7 (ii)

The method I used was one that I learnt for C1. I differentiated the curve and made the value for x equal to 4 to find the gradient at the point (4,7). Then I used y-y1=m(x-x1) to find out the equation of the tangent. After doing this I made y=0 to find where the tangent crossed the x axis. Then I integrated the tangent finding the area between x=4 and x=5/3. I then subtracted the value for the area under the tangent from the value for the area under the curve to get 37/30.

Reply 73

joostan

13

Original post by HayyanN

Can someone please explain how they did 7 (ii)

Integral - triangle of tangent with x-axis.
Find tangent's equation:

Spoiler

Area:

Spoiler

(edited 10 years ago)

Reply 74

The_Blade

6

i got about 48 marks which is about a C.... :frown:

Reply 75

The_Blade

6

Original post by RooRoo1

Thanks for pointing this out. I'm not particularly gifted with maths, and my teacher got really ill so we've basically taught ourselves most of the c2 & s1 stuff. I didn't find the paper that easy, I think I got around 45-52 marks (I can't remember some of the answers I put). So just wanted to say thanks for putting it out there that not everyone found it easy!

got about the same marks as you. what grade do you think that'll be?

Reply 76

Whyllee

I got 59-63 marks is that an A? :frown:

(((((((((((

Reply 77

owl 1996

5

For 9ii I put (x+0.5)(2x+2)(2x-3) , which multiplies out the same- does anybody know if i will still get the marks- thanks :smile:

Reply 78

joostan

13

Original post by owl 1996

For 9ii I put (x+0.5)(2x+2)(2x-3) , which multiplies out the same- does anybody know if i will still get the marks- thanks :smile:

MrM is an OCR examiner - he'll be able to tell you if you post your question here.
If it multiplies out the same, your working is correct, and the final answer is the same you will obtain full credit. :smile:

(edited 10 years ago)

Reply 79

Good@Math

Original post by geekD96

THANKS AND how on earth did u manage to get the paper?!:O