A Level Maths - C3 (Mei) OCR - June 19 2018

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Reply 20

summerpicnics

question 3 was the half lives and question 4 was the one ppl (and me lol) have got 0.5 something for

Reply 21

elsiej

Original post by Luxyaaa

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I think I got (0.544,0.519) for Q5

I got this too!

Reply 22

ccpdawg

Q8 integral i got 23/8 - 4ln2

Original post by AV_Luke

Copy and paste of my answers from another thread- not sure how correct they are, any thoughs?

Q1 ii) Got -6.
Q2) One was even, one was neither, one was odd & one was periodic with period 180 degrees. -Not sure on this question.
Q3) Can't remember?
Q4i) 25% after 2 half lives.
Q4ii)k=0.0048 (or 0.048, can't remeber)
Q5) Something like (0.544,1.519)
Q6I)5pi/5
Q7) Had to facotrise and see it was n(n-1)(n-2). So one was a multiple 2 and one was a multiple of 3 so it was divisible by6.
Q8iii) Had to work out the trapezium and minus the integral. I remember it being 0.101, but you ahd to give it in exact form which I can't remember.
Q9i) It was a stretch s.f 2 on y and a translation by vector (2,0) I think.
ii) One was (3,0), the other was (4,ln(4))
iii) Answer was 1.77 I think, exact form was something like 4ln(2) -1.

Reply 23

Luxyaaa

Guys why was the inverse question worse 4 marks?

Reply 24

Ivoryivory

Original post by ccpdawg

Q8 integral i got 23/8 - 4ln2

Was it not 4ln(2) -3

Reply 25

Luxyaaa

Original post by Luxyaaa

Guys why was the inverse question worse 4 marks?

*worth

Reply 26

Jemimalily

I thought it was a blessing, best paper I could’ve hoped for, but almost everyone else who did it at my college thought it was really bad

Reply 27

Daribig98

Original post by AV_Luke

Dude for the coordinates you were meant to put it into exact for, not round up or down.

Reply 28

Luxyaaa

Original post by Ivoryivory

Was it not 4ln(2) -3

I got 23/8-4ln(20

Reply 29

Luxyaaa

Original post by Daribig98

Dude for the coordinates you were meant to put it into exact for, not round up or down.

I dont think there's an exact from tho

it didn't say exact

And im thiking the grade boundaries will be 56-58 for an A, thoughts?

Reply 32

H4mbo

think this was the graph

Reply 33

Luxyaaa

Original post by Daribig98

And im thiking the grade boundaries will be 56-58 for an A, thoughts?

Isn't it out of 90??

Reply 34

Daribig98

Original post by summerpicnics

it didn't say exact

I could have sworn they asked for exact form, did they ask you to round it to x sf?

Reply 35

Zgogol18

1. -3y/4x as dy/dx
dy/dt=-6
2. 1. Odd 2.neither, periodic 3. Even
3. 25%, k=0.048
4.x=0.55, y=0.29
5. Modulus graph x=-1/3
6. 5pi/6, y=sin(2x-pi)/4
7. Equation of the line x-4y+3=0, gradient=1/4. Point Q was 3/4 for me, the area was 23/8-4ln2
8. When integrated lnx had to times my 1
9. For the last part of the last question I have found the area for lnx between 4 and 1 I think, than found the area between 3 and 4 for 2ln(x-2), though I did a really weird thing. I have integrated 2ln(x-2) by parts and within that I had to integrate udv/dx by substitution. Then subtracted the areas.
10. For point Q for question 9 (not the one with trapezium) I got something like (4,2ln2) can’t remeber and for P I got 3

Reply 36

JaredzzC

Original post by Daribig98

And im thiking the grade boundaries will be 56-58 for an A, thoughts?

Same.

Previous years have been around that mark for an A and this paper was no harder than previous' years papers - it was actually quite nice.
Arguably the only challenging question was the last one. The actual method was fine but it was just realising what you had to do/use to get the answer.