Arsey's S15 FP2 Model answers (in first post)

Reply 20

Beasttty

6

The easy questions normally became hard on this paper, and the normally hard ones were easy.

Reply 21

CammyG

1

Original post by physicsmaths

Q1 prt a is both
Part b isnt it just x>1

Posted from TSR Mobile

I have to agree with this, though it is only one mark I must say I'm sure it's x>1 for 1(b). This is because in the exam I roughly drew both graphs, and as the 12/(x+3) becomes modulated, the x+2 graph can only ever be above the other graph after x=1. I would like to know what Arsey thinks as well.

Reply 22

InOrbit

9

Original post by Beasttty

The easy questions normally became hard on this paper, and the normally hard ones were easy.

The paper tested your trigonometry and calculus skills much more than it did with other papers. Other than that, the methods and procedures themselves were quite straightforward.

Reply 23

cliverlong

8

Q4. Power of square bracket on penultimate line should be 2 not n ?

Q2. Given ranges for x are answer for part a. For part b, only x> 1? Quick sketch of both sides will confirm this

Clive

Reply 24

CammyG

1

Original post by Arsey

Quite reasonable on the whole - expect standard boundaries

1(b) x>1. No? Modulus sign provides this answer only.

Reply 25

ThomasNugent

yeah for 1b just type it into wolfram alpha and youll see :smile:

http://www.wolframalpha.com/input/?i=x%2B2%3E12%2F%7Cx%2B3%7C

Reply 26

fatart123

15

How many marks will I lose for 2c) if I used w = z^(3/4) and found all 4 correct answers? Serious question btw, worried about something

Reply 27

randomuser1

2

Original post by Arsey

Quite reasonable on the whole - expect standard boundaries

Good paper overall, really annoyed at myself, I got the IF= sinx for the 1st order differential, got the right answer (i think) then second guessed myself and changed my whole answer from the IF onwards, so the examiner won't see it. I would guess thats 3/4 marks dropped depending if they see me multiplying through by sinx? Other than that I do believe I got full marks :colondollar:

Reply 28

darkdrifter10

2

will i lose any marks for putting 3Ccosecx for the last term in the FODE question?

Reply 29

InOrbit

9

Original post by fatart123

How many marks will I lose for 2c) if I used w = z^(3/4) and found all 4 correct answers? Serious question btw, worried about something

2 at most.

Reply 30

SkyWarrior

How many marks would I lose for integrating -sinx to -cosx for the first order differentials question? I got everything else right but I'm worried I lost 2 marks - 1 for not integrating that properly and another final answer mark. Aiming for an A*, any idea what 71/2 raw marks would give in UMS? thanks.

Reply 31

ThomasNugent

Original post by Alex:

2 at most.

really? i would have thought if he got all the correct roots in the end then it wouldn't matter?

They normally have marks for alternative methods as well

Reply 32

InOrbit

9

Original post by SkyWarrior

How many marks would I lose for integrating -sinx to -cosx for the first order differentials question? I got everything else right but I'm worried I lost 2 marks - 1 for not integrating that properly and another final answer mark. Aiming for an A*, any idea what 71/2 raw marks would give in UMS? thanks.

I would say no more than 3.

Remember, if you are aiming for an A* in further maths, then you don't need 90ums in FP2. You just need 90ums overall in three A2 units or in other words, 270ums from your A2 exams. Missing by a few ums in FP2 is normal for a lot of candidates, and it is fine as long as you are strong in another area, like statistics or mechanics.

Reply 33

InOrbit

9

Original post by ThomasNugent

really? i would have thought if he got all the correct roots in the end then it wouldn't matter?

They normally have marks for alternative methods as well

Hence, 2 at most.

Two if they're feeling the answer is "cso". You see that a lot in mark schemes, and it basically means correct solution only.

One if they allow follow through marks.

No marks if they see that using 3pi/4 is completely equivalent. Whilst it is equivalent in this case, it is not equivalent in all cases, and certainly isn't a correct usage of De Moivre's theorem.

Reply 34

kprime2

20

so for 5(a) for the show that it's a circle under W. I got everything right but then accidently made a silly sign slip resulting in the wrong cartesian equation. But the working out before it and all the numbers before it was correct. this then resulted in the wrong centre and radius. well i got -0.8 coordinate for u for the centre but the other one I didn't get 0. How many marks lost?
then for the next part I drew the circle [incorrect] i got from previous part and shaded the inside? Is there room for ECF marks here or should I consider all 2 marks lost for it?

Reply 35

sol.smith

To integrate the cos2xsinx you had to use double angle formula to get 2cos^2xsinx - sinx then integrate that. It was a tricky paper, I couldn't do the method of two differences either but apparently it's easier than it looks.. For the polar question I got a^2(81rt3/16 + 9/4pi). I struggled to convert the differential equation on Q8 so I just adjusted it to make it work in hope of fluking it haha. Wasn't my best paper but hoping for 85+ ums

Reply 36

fatart123

15

Original post by Alex:

Hence, 2 at most.

Two if they're feeling the answer is "cso". You see that a lot in mark schemes, and it basically means correct solution only.

One if they allow follow through marks.

No marks if they see that using 3pi/4 is completely equivalent. Whilst it is equivalent in this case, it is not equivalent in all cases, and certainly isn't a correct usage of De Moivre's theorem.

Well, I ended up with w = 2sqrt(2)(cos(pi/2 + 3kpi/2) + isin(pi/2 + 3kpi/2)) and used k = 0, -1, 1 and -2.

Reply 37

SkyWarrior

Original post by Alex:

I would say no more than 3.

Remember, if you are aiming for an A* in further maths, then you don't need 90ums in FP2. You just need 90ums overall in three A2 units or in other words, 270ums from your A2 exams. Missing by a few ums in FP2 is normal for a lot of candidates, and it is fine as long as you are strong in another area, like statistics or mechanics.

Thanks, I also slipped up in the shading region R question so it looks like I'll be getting around 71. I thought I was strongest in FP2, so I'm hoping the S2 and M2 papers aren't that bad. Thanks to vectors, conics and matrices, I'm only aiming for an A in FP3 lol

Reply 38

username1200599

12

Ugh, on the transformation question I somehow managed to copy down my -4/5 as a -4/25 when getting the last line for my circle equation. This ended up giving me the wrong radius only, how many marks would that drop me do you reckon?

Reply 39

Bendak

2

For the roots question, they didn't state the range for theta, so I assume they want us to use the principal argument? Doesn't that mean that the only k's we can use are 0, 1, -1 and -2? I know that they would essentially give the same final answers but would there be method marks on this?

Arsey's S15 FP2 Model answers (in first post)

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you