x Turn on thread page Beta
 You are Here: Home >< Maths

# Mr M's OCR (not OCR MEI) Core 1 Answers May 2013 watch

1. (Original post by Dugald)
I didn't put question 8 in integer form.

On question 10 I got that k=-5 but when putting k back into the original equation and differentiating it I got dy/dx=-3x^2-6x+4-k to be dy/dx=-3x^2-6x+4-5 instead of dy/dx=-3x^2-6x+4-(-5) so got dy/dx=-3x^2-6x-1.

I carried this error forwards into the last part of the question and did dy/dx=9, then put it into quadratic form but it had no real roots. I couldn't work out where I went wrong so in the last few minutes i just went with it and proved that it had no real roots which I knew was wrong.

How many marks will I lose in total?
8) drop 1

10)i) drop 1

10iii) drop 2
2. (Original post by Mr M)
x.
Hey Mr M, thank you so much. How many marks would I lost if:

for 5i) sketch I labelled -2 and 2 on the x-axis but still got the actual sketch of the curves correct?

for 7ii) I somehow missed off the 0 and put x<5?
3. I'm off for a bit folks as I have work to do. Back later. Don't private message me please - ask questions here.
4. Mr M, what was question 8?
Thanks
5. Would someone mind posting the working out for the last part of the last question, I cant get my ead around it, thank you.
6. (Original post by Mr M)
That's ok then! I'll post C2 answers on Friday afternoon.
Mr M, for the last question for the stationary points i differentiated, equaled it to 0 as the gradient=0, but somehow got k= -4 instead of -5. How many marks would I lose for the answer?

Also for the final part to the last question, i stupidly did -18-9=-9. This means I got the co-ordinates as (-2,-9). However I factorised correctly and got the correct co-ordinate for x, how many marks would I lose for that? Thanks!
7. (Original post by AspiringDoctor)
Hey Mr M, thank you so much. How many marks would I lost if:

for 5i) sketch I labelled -2 and 2 on the x-axis but still got the actual sketch of the curves correct?

for 7ii) I somehow missed off the 0 and put x<5?
The curve doesn't touch the x axis so I'm not sure why you labelled anything there?

7ii) drop 3 marks
8. For Q7 part 2 I missed the 0 boundary, would I only lose 1 mark for this?
9. Hello Mr M,

1.For Question 5(iii), I put, A stretch parallel to the Y-axis by a scale factor of 2. I thought it was going from 1/x^2 to 2/x^2, thats why I did that. Will I get any marks?

Also, for Question 6, I completed the square, but got (x-0)+(y-4)=40 , and for my Centre I put (0,4) and Radius Sqrt(40).
Because this part of the question was wrong, the Point B on 6(ii) was different too, but the write answer using (0,4)

Thanks,
C94
10. (Original post by Mr M)
Yes.
Yay thank you! And also thanks for the answers.

Posted from TSR Mobile
11. (Original post by Mr M)
I think you will lose 2 accuracy marks.
Thank you!! If this is true you have made me feel so much better!!! And thank you for the answers as well
12. (Original post by Mr M)
C2, C3, C4, FP1, FP2, M1, M2. These are the ones I teach.
Ahh, not S1? S1 will be a killer this year. It's the only Maths exam (from C1-4, FP1, M1, M2, S1) I'm underprepared for, and the papers have gotten more and more difficult every series since June 2011 (which itself was trickier than ever before). I have a feeling they will culminate this year in a "big bang". And the 100 UMS boundary will be 60. Which isn't good ...
13. Suppose I put two answers down with all workings, one is incorrect and one is right. How marks will i lose? ...This is for the last question

Now if only I could remember what my answers were
15. I put +/- 1/2 as a route instead of just as 1/2 will I still get the mark?
also think did the correct method but the wrong answer for part (iii) on the last question will I still get method marks? And if so how many?
16. Hey Mr M i compeleted the square for 7(ii) and wrote x= 5/2 +/- root 50/8 would i lose all marks
17. Hi I put down (0,-9) and (-2,-27) for the last question but stated A as being (0,-9) cos I thought that fit the equation given. Any ideas how many marks I'll lose?
18. Can't remember if for Q4 ii) it asked to differentiate to find the minimum point? I just used the values I got from completing the square...
19. Mr M what if I wrote question 3 out like 36X^-4??
20. (Original post by Mr M)
Mr M's OCR (not OCR MEI) Core 1 Answers May 2013

1. (i) (2 marks)

(ii) (1 mark)

(iii) (1 mark)

2. or (5 marks)

3. (i) (3 marks)

(ii) (2 marks)

4. (i) (3 marks)

(ii) (3 marks)

(iii) (2 marks)

5. (i) Correct sketch (2 marks)

(ii) (2 marks)

(iii) Stretch scale factor parallel to y axis (2 marks)

6. (i) Centre and radius (3 marks)

(ii) (2 marks)

7. (i) (2 marks)

(ii) (5 marks)

8. (7 marks)

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

(ii) OR (either will be marked correct) (3 marks)

(iii) (4 marks)

10. (i) (7 marks)

(ii) Minimum (2 marks)

(iii) (5 marks)

I'll be around to answer questions shortly.
hey, for question 10 iii) i dy/dx the curve(-3x2-6x+9) then equated to gradient of tangent(9) but i ended up getting x=-2.5 and subbing into curve to get -35/8 how many marks will i lose ?

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: May 20, 2014
Today on TSR

### I've studied the wrong subject

...Should I go back to school?

### Should I complain about my supervisor?

Poll
Useful resources

Can you help? Study help unanswered threadsStudy Help rules and posting guidelinesLaTex guide for writing equations on TSR

## Groups associated with this forum:

View associated groups

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