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

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Reply 40

Rrobba

What was question 7i? Show that...what?

Reply 41

tgtips372

Out of interest, am I the only one who put 19/10 as the area on q7ii)? Everyone seems to have got 37/30 and I'm one of only two people I know who got 19/10, but I can't see what I did wrong :frown:

Reply 42

owl 1996

Original post by chuckynoriss

7ii) how is it 37/30 because you do the integration of curve- tangent from 1 to 4 and 3/2( 1.5) is bigger than 1 so lower limit is 1

The line y=3x-5 crosses the x axis at i think it was (5/3) not one, so it you have to intergrate between 4 and 5/3 instead, which gives the area under the line as 8.1666 :smile:

Hope that helps

Reply 43

zcQ

What was question 3ii. ??

Reply 44

tgtips372

Thanks

do you reckon I'll lose one accuracy mark if I integrated between 4 and 1?

Reply 45

owl 1996

probalby - and maybe one for the answer also- but you should hopefully get all the method marks :smile:

Reply 46

Good@Math

Original post by Hannburger

Hi, what was question 5?? (:

Added question paper

Reply 47

Good@Math

Original post by Paribas01

What was question 3ii. ??

Added question paper

Reply 48

tgtips372

Yeah, I suppose so :s-smilie:

thanks again!

Reply 49

Majeue

Original post by Rrobba

What was question 7i? Show that...what?

Show that 1.3^n > 1.52... Something along those lines can't remember exact no's

Reply 50

Good@Math

Original post by sugartown

Can someone explain why the first one was 6.3 and not 9.56 or something? I got 6.3 before I x the bracket and then 6.3 x 3/2? So confused and feel a bit stupid considering it was such easy marks

I got 9.56 first time, but think I made a mistake so it's 6.39. The start of trapezium rule is 1/2 x h (h=width, in question given as 2) so it's 2/2 (=1) x6.39

Reply 51

tgtips372

Show that 1.3^N_< 91 I think, can't remember which way around the inequality sign was

Reply 52

sugartown

Original post by tgtips372

Hey

the reason you don't multiply the 6.3 by 3/2 is because the trapezium starts with h/2, there were 3 strips but the width of each strip was 2, so the h/2 was equal to 2/2 so basically it stays as 6.3. Hope that helps! :smile:

Ohhhh so I put 3/2 rather than 2/2 which is obviously 1! Argh so annoying! Think I probably would have got a B anyway as the paper did not go my way so didn't make too much of a difference!

Reply 53

Majeue

I think I got >63 , does anyone know the highest grade boundaries for c2 there have been in previous years?

Reply 54

sugartown

Original post by Good@Math

I got 9.56 first time, but think I made a mistake so it's 6.39. The start of trapezium rule is 1/2 x h (h=width, in question given as 2) so it's 2/2 (=1) x6.39

Argh wish I had looked back at it and realised! Thanks for the help

Reply 55

joostan

Since there's not one in the OP:
Worked Solution to 8ii)

a^x = 4b^x[br]\Rightarrow x\log_2a = 2+x\log_2b [br]\Rightarrow x(\log_2\frac{a}{b}) =2[br]\mathrm{as} \ ab=2 \Rightarrow b=\frac{2}{a}[br]\Rightarrow x(\log_2\frac{a^2}{2}) = 2[br]\Rightarrow x = \dfrac{2}{log_2a - 1}

(edited 10 years ago)

Reply 56

chubuking

Original post by joostan

Since there's not one in the OP:
Worked Solution to 8ii)

a^x = 4b^x[br]\Rightarrow x\log_2a = 2+xlog_2b = x(\log_2\frac{a}{b})[br]\mathrm{as} \ ab=2 \Rightarrow b=\frac{2}{a}[br]\Rightarrow x(\log_2\frac{a^2}{2}) = 2[br]\Rightarrow x = \dfrac{2}{log_2a - 1}

same method i used :smile:

Reply 57

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:

Reply 58

joostan

Original post by chubuking

same method i used :smile:

Lol - quite a nice q. The C2 I took in jan didn't have a nice logs question :tongue:

Reply 59

Majeue

Original post by Good@Math

GRADE	Jan 11	June 10	Jan 10	June 09	Jan 09	June 08	Jan 08	June 07	Jan 07	June 06	Jan 06
MSM	75	75	75	75	75	75	75	75	75	75	75
A*	-	-	-	-	-	-	-	-	-	-	-
A	61	61	58	60	65	60	60	62	n.a.	n.a.	n.a.
B	54	54	50	52	57	52	53	55	n.a.	n.a.	n.a.
C	47	47	43	44	49	44	46	48	n.a.	n.a.	n.a.
D	40	41	36	37	41	37	39	41	n.a.	n.a.	n.a.
E	33	35	29	30	34	30	33	35	n.a.	n.a.	n.a.