OCR C4 (not mei) 18th June 2013 revision

Reply 660

AlesanaWill

16

Original post by ActaNonVerba

Didn't it say acute angle, which would be 180-your answer? I put both down just in case

I don't think it specified acute.

Original post by strikerextreme

for this question i solved the diff equation but my answer wasnt expressed as r=

how many marks would i lose ?
i got the c value

You'd probably only lose 1 for not being in the correct form.

Reply 661

Lizzie232

11

Just

That is all.

Reply 662

kark94

Original post by Kayoz

Does any one remember how many marks q9 was???

3+4+2 = 9 marks in total

Reply 663

overfield

Original post by SJ12345

Did anyone get 0.136 on any part of question 10?

I got that for the decimal estimate for the value of 100/729, 10ii.

Reply 664

aBanna

Right so for 7. (ii). I had the 2 vectors r=(-1, -3, -9) and s=(1, 1, 5) but I went in to auto pilot and did r x s, got -1*AD, will I get marks for using alternate method?

Reply 665

Kayoz

Original post by kark94

3+4+2 = 9 marks in total

thx!
i prob lost 4 marks for stupidly re-arranging to get t=-1

Reply 666

username973061

What do people think the volume of the pyramid was?

Reply 667

XingBairong

what do you guy think about the grade boundaries?

I'm hoping for 64 for A* :L

Reply 668

HypErTwisT

2

Original post by XingBairong

what do you guy think about the grade boundaries?

I'm hoping for 64 for A* :L

Im thinking they will be semi low, compared to other papers I thought it was quite hard, 64 will easily be A* I reckon.

Reply 669

junaid_k17

5

for the parametric question i gt dy/dx = 2-2/t

i then did dy/dx = 0, and got t=1.

i then subbed it back into the parametric equations to get stationary points.

i then found dy/dx for t=2 and t=-1.

i the said point was a max point...

do you fink thats rigght, any one else do that?????

Reply 670

Namige

17

Original post by junaid_k17

for the parametric question i gt dy/dx = 2-2/t

i then did dy/dx = 0, and got t=1.

i then subbed it back into the parametric equations to get stationary points.

i then found dy/dx for t=2 and t=-1.

i the said point was a max point...

do you fink thats rigght, any one else do that?????

t is 1 and it is the minimum point as the second derivative > 0.

Reply 671

junaid_k17

5

also what do u fink a C grade will be, cuss i fink i gt 43/72????????????

Reply 672

ActaNonVerba

What's the theory for q10 to get 1/10.. I made a random guess and it worked, but can someone explain how you would get 1/10.. And explain 10i) I couldn't do that

Reply 673

a10

19

Original post by ActaNonVerba

What's the theory for q10 to get 1/10.. I made a random guess and it worked, but can someone explain how you would get 1/10.. And explain 10i) I couldn't do that

10i) was just expansion so you had x(1-x)^-3 and u expand the brackets first and multiply ur answer by x and you got the answer they asked for!

Reply 674

FiftyFive

2

I made a really weird way of estimating 100/729, I multiplied by the denominator and just let x = 100/729. This is completely valid, but will this get me the marks?