[Forums^^]

(Original post by Mr M)
yes and no to your two questions

If you state reflected vertex coordinates as (-2,4K) does that count as an implied answer. x=-2

Seeing as I calculated K by saying 4K=20.

[Mr M]

(Original post by Forums^^)
If you state reflected vertex coordinates as (-2,4K) does that count as an implied answer. x=-2

Seeing as I calculated K by saying 4K=20.

Possibly.

[somaiyar]

For 8iii I got the minimum value but didn't get the maximum value, how many marks would I get? Thanks

[Mr M]

(Original post by somaiyar)
For 8iii I got the minimum value but didn't get the maximum value, how many marks would I get? Thanks

drop 1 I expect

[momories]

Question 9.iii)
I originally wrote the wrong answer, but then ended up writing the correct one. But then I forgot to cross out my wrong answer.
What will happen? So worried about this...

I don't remember getting any answers for question 8, but hopefully they'll be some method marks in there. What do you think the grade boundaries will be for this paper?

[Mr M]

(Original post by momories)
Question 9.iii)
I originally wrote the wrong answer, but then ended up writing the correct one. But then I forgot to cross out my wrong answer.
What will happen? So worried about this...

I don't remember getting any answers for question 8, but hopefully they'll be some method marks in there. What do you think the grade boundaries will be for this paper?

I can't tell you how that will be treated. Sorry.

[Mr M]

(Original post by kizuna123)
I used two extra bits of paper to answer questions on this paper but foolishly forgot to my name or candidate number on them. They're attached to my answer booklet. which has all the relevant info, by treasury tag. Does anyone what I should do in this situation and if it would be possible to rectify this mistake?

You don't need to do anything. They will be scanned and marked.

[As_Dust_Dances_]

I calculated that I may have got 45/72 (if I'm lucky), partly because I messed up qu8 and qu9, however I did use the discriminant on last part of 9 but somehow got the wrong value of k. Also for the tangent question, I got the wrong gradient, will there be method marks still available even if I got the wrong value of k and gradient?

[-skill-]

for the very last question, how many marks am i likely to drop if i put 2±2root2 instead of -2±2root 2?
and also 7i) if i did the working for the mass decreasing by 25% instead of 75% would i gain any marks there?

[jedhemsley]

on the volume of revolution i messed it up by saying a bracket to the -4 integrated to the bracket to the -5, but did everything else right. would you get any credit for that?

[nffc-b]

for the last question i didnt cancel down the surds on the coordinates, would i get marked down for that?

[Mr M]

(Original post by -skill-)
for the very last question, how many marks am i likely to drop if i put 2±2root2 instead of -2±2root 2?
and also 7i) if i did the working for the mass decreasing by 25% instead of 75% would i gain any marks there?

drop 1 mark for accuracy and you might get 1 mark in 7

[Mr M]

(Original post by jedhemsley)
on the volume of revolution i messed it up by saying a bracket to the -4 integrated to the bracket to the -5, but did everything else right. would you get any credit for that?

It is a common mistake but you will have several marks.

[Mr M]

(Original post by nffc-b)
for the last question i didnt cancel down the surds on the coordinates, would i get marked down for that?

no

[CJAW]

(Original post by Mr M)
Mr M's OCR (not OCR MEI) Core 3 answers January 2012


1. Show (3 marks)


2. (5 marks)


3. (7 marks)


4. i) 2 and 5 (4 marks)

ii) (3 marks)


5. i) 26 and 4 (2 marks)

ii) Reflection in line y = x (2 marks)

iii) 206 (4 marks)


6. i) (2 marks)

ii) Show (3 marks)

iii) (7.441, 11.888) (5 marks)


7. i) a) 10.5 years (3 marks)

b) 2.73 grams per year (3 marks)

ii) 27.8 grams (3 marks)


8. i)

k = 8 (3 marks)

ii) (2 marks)

iii) 2 and -2/3 (5 marks)


9 i) Translation -2 units parallel to x axis

Translation -4 units parallel to y axis

Stretch scale factor k in y direction (5 marks)

ii) (2 marks)

iii) k = 5

(6 marks)

Can you confirm as to whether question 6i was asking for dy/dx or dx/dy?
I'm sure it gave the expression as x= ln(etc) and then asked you to find dx/dy
Thanks

[Mr M]

(Original post by CJAW)
Can you confirm as to whether question 6i was asking for dy/dx or dx/dy?
I'm sure it gave the expression as x= ln(etc) and then asked you to find dx/dy
Thanks

Yes it was dx/dy - just a typo so you don't need to worry!

[levantine]

(Original post by Mr M)
Mr M's OCR (not OCR MEI) Core 3 answers January 2012


1. Show (3 marks)


2. (5 marks)


3. (7 marks)


4. i) 2 and 5 (4 marks)

ii) (3 marks)


5. i) 26 and 4 (2 marks)

ii) Reflection in line y = x (2 marks)

iii) 206 (4 marks)


6. i) (2 marks)

ii) Show (3 marks)

iii) (7.441, 11.888) (5 marks)


7. i) a) 10.5 years (3 marks)

b) 2.73 grams per year (3 marks)

ii) 27.8 grams (3 marks)


8. i)

k = 8 (3 marks)

ii) (2 marks)

iii) 2 and -2/3 (5 marks)


9 i) Translation -2 units parallel to x axis

Translation -4 units parallel to y axis

Stretch scale factor k in y direction (5 marks)

ii) (2 marks)

iii) k = 5

(6 marks)

Can you show me how to show 6ii) where you had to show the y coordinate satisfies an equation of some sort. I was just totally blank on that one

[Alex J]

what are the grade boundaries likely to be in terms of raw marks??

[JongKey]

(Original post by levantine)
Can you show me how to show 6ii) where you had to show the y coordinate satisfies an equation of some sort. I was just totally blank on that one

You just had to flip your dx/dy to make dy/dx and then make it equal to 4. Then do some rearranging and you would get the answer they got. I was stuck on it for quite some time as well.

[levantine]

(Original post by JongKey)
You just had to flip your dx/dy to make dy/dx and then make it equal to 4. Then do some rearranging and you would get the answer they got. I was stuck on it for quite some time as well.

I knew you have to flip it to get dy/dx but why do you make it equal to 4?