Maths HL P 1 - aftermath

Xevkin

EuropeanSon wrote: »

Q1(c) I multiplied the two factors before dividing, it made it much much easier.

I did X^2 minus x the sum of the roots plus product of the roots :P but what ever :P

**Timbuk2**

Guys, I would advise you to just forget about today's paper, and concentrate on your next exams. Hearing other people say they did well, and people posting answers you didn't get will only dishearten you.

Remember, no matter whether the paper is easy or hard, the overall grade curve must be the same. Therefore an easy paper will be marked very hard, and a hard paper will be marked very easy. Often people who say they 'definitely got an A' get screwed over by a hard marking scheme, such as in 2005 (I think) where they docked you 7 marks (!!!) for forgetting the Absolute Value signs in the perpendicular distance formula.

Put it behind you. You can compare with everybody on August 18th. Concentrate on Paper 2 - best of luck!

teacher30

Reillyman wrote: »

Oh gimmee a break! I had someone else say this to me earlier on. The way you've phrased it makes it sound like it's a bad thing for us having done well. Personally I worked really hard at Maths all year long and am well entitled to be as god damn arrogant and confident as I want. In maths you get what you deserve most of the time so people should stop looking at things to blame and start looking at themselves if they feel they done bad.

Congratulations on doing so well - and i don't doubt that you deserve it. I was merely trying to help others feel better, that was all. I was downplaying your success. Well done. I'll keep my mouth shut from now on.

teacher30

teacher30 wrote: »

Congratulations on doing so well - and i don't doubt that you deserve it. I was merely trying to help others feel better, that was all. I was downplaying your success. Well done. I'll keep my mouth shut from now on.

OOOPS - meant to say: I WASN'T downplaying your success.

MyHair

Paper 2 is easier than paper 1 in my opinon. Just do well in it and you shall pass!

teacher30

**Timbuk2** wrote: »

Guys, I would advise you to just forget about today's paper, and concentrate on your next exams. Hearing other people say they did well, and people posting answers you didn't get will only dishearten you.

Remember, no matter whether the paper is easy or hard, the overall grade curve must be the same. Therefore an easy paper will be marked very hard, and a hard paper will be marked very easy. Often people who say they 'definitely got an A' get screwed over by a hard marking scheme, such as in 2005 (I think) where they docked you 7 marks (!!!) for forgetting the Absolute Value signs in the perpendicular distance formula.

Put it behind you. You can compare with everybody on August 18th. Concentrate on Paper 2 - best of luck!

Probably the most helpful and true comment i've read this evening!!

karen-xxxxx

NumberZeroNine wrote: »

Okay, so I'm going to sleep now but if anyone who feels that they did really well on a certain bit please copy this with that bit filled in.

It'd be nice to have a complete solution for people to look at.
When we're done we can post them in a seperate thread for clarity and easy-access.






Question 1 (A)
x^2 -6x+t = (x+k)^2
x^2 -6x+t = x^2+2kx+k^2

=> -6=2k , t=k^2
=> k+-3 , t=9

Question 1 (B)
Real Roots, => b^2-4ac > 0
(-4p-1)^2 -4.2p > 0
16p^2 +8p +1 -8p > 0
16p^2 +1 > 0
True, as perfect square plus positive number must > 0

Question 1 (C)

(x-2) factor f(x)
when you long divide you get
d = -2c-4b-8
(x+1) factor f(x)
when you long divide you get
d = c-b+1

let them equal
c-b+1 = -2c-4b-8
3c = -3b-9
c = -b-3
(ii)
d = -2c-4b-8
d = -2(-b-3)-4b-8
d = -2b-2
(iii)
c=b+n, d=b+2n
-b-3=b+n, -2b-2=b+2n
2b=-n-3, 3b=-2n-2
b=(-n-3)/2, 3.(-n-3)/2=-2n-2
-3n-9=-4n-4
n=5
b=-4,c=1,d=6

Question 2 (A)


Question 2 (B)
it tells you alpha > 0, Beta > 0

so -4 isn't a possible solution, nearly didn't catch that one.

Full Solution;

A^2.B^2 = 16
A^2+B^2 = 12

(i)
(A.B)^2 = 16
A.B = rt(16) = 4 (-4 isn't a solution because of phrasing of Q)

(ii)
(A+B)^2 = A^2 +2.AB +B^2
(A+B)^2 = (A^2+B^2) +2.(AB)
(A+B)^2 = (12) + 2.(4)
(A+B) = rt(20)
(A+B) = 2.rt(5)

Question 2 (C)

Question 3 (A)

Question 3 (B)

Question 3 (C)

Question 4 (A)

Question 4 (B)

Question 4 (C)

Question 5 (A)

Question 5 (B)

Question 5 (C)

Question 6 (A)

Question 6 (B)

Question 6 (C)

Question 7 (A)

Question 7 (B)




Question 7 (C)
when diff.ing it;
let u(x)=(1+X), v(x)= ln(1+X)
=> u'(x)=1, v'(x)=1/(1+X)

f'(x) = [v(x).u'(x)+u(x).v'(x)]
f'(x) = [1.ln(1+X)+(1+X)/(1+X)]
f'(x) = [ln(1+X)+1]

f''(x) = 1/(1+X)

At turning point; f'(x) = 0

[ln(1+X)+1] =0
ln(1+X) = -1
1+X = e^-1
X = e^-1 -1
X = 1/e - e/e
X = (1-e)/e

Sub into F(x)

y = f((1-e)/e)
y = ( (e+1-e)/e ).ln( (e+1-e)/e)
y = (1/e).ln(e^-1)
y = -1/e

At local Min f''(x) 0
At local Max f''(x) 0

F''((1-e)/e) = 1/((e+1-e)/e)
= 1/(1/e)
= e
> 0
Therefore Min.

Question 8 (A)


Question 8 (B)
Limits 0-1, 1-3
A = Iy.dx(0-1) + Iy.dx(1-3)
A = [3x4-16x3+18x2](0-1) +[3x4-16x3+18x2](1-3)
A = [(5) – (0)] + [(-27) – (5)]
A = 5 + |-32|
A = 37 square units

Question 8 (C)

Question one c? Are you positive of your values? I got b=4, c= -7 and d = -10. I then put those values into the cubic and used the factors of x to verify, could be wrong though.

EuropeanSon

Xevkin wrote: »

I did X^2 minus x the sum of the roots plus product of the roots :P but what ever :P

Just to be awkward, was it? The examiner will love my paper, minimal space used up, nothing crossed out, all (hopefully) right answers. It should take him/her 5 minutes to correct.

Xevkin

Went to a new double page for every question. But had to be a LITTLE bit awkward; gotta have my kicks somehow

Ditzie

EuropeanSon wrote: »

Then they should. You need to cover the whole course, it's like the clowns who only did Boland in English.

Edit: directed at johnmcdnl

we didn't actually hav time as our techer was out for 8 weeks and we had this clown who spent all that time on integration! so you might want to think before you are so arrogant!
so yeah johnmc i totally agree!

MollyJayne

karen-xxxxx wrote: »

Question one c? Are you positive of your values? I got b=4, c= -7 and d = -10. I then put those values into the cubic and used the factors of x to verify, could be wrong though.

It was -4, 1, and 6
You must have got b as 4 instead of -4?
I got c wrong, forgot to change signs =[
But 4, -7, -10 don't fit the equation!
So, it is -4, 1 and 6

randylonghorn

theowen wrote: »

I never started this thread. I did ordinary level maths to boot!:p

Sorry, Owen, I merged different threads / split one main one off again earlier to try to keep stuff in one place, and your post seemed the obvious place to start! You'll survive in this august company!

And only one person spotted my little pun, I'm very disappointed!

Reillyman wrote: »

Oh gimmee a break! I had someone else say this to me earlier on. The way you've phrased it makes it sound like it's a bad thing for us having done well. Personally I worked really hard at Maths all year long and am well entitled to be as god damn arrogant and confident as I want. In maths you get what you deserve most of the time so people should stop looking at things to blame and start looking at themselves if they feel they done bad.

... did badly, actually.

And you see, Reillyman, I would normally never correct someone that bluntly, but that's the kind of reaction arrogance engenders. I'm sure you heard the term "hubris" mentioned in your English classes?

Of course it's not a bad thing that you did well. It's something to celebrate. If you worked your arse off all year and that hard work paid off, that's twice as worthy of celebration.

But there's no need to put down others, or turn yourself into Ross-O'Carroll-Kelly-from-Mayo-but-who-can-do-maths!

Maths definitely depends a lot on hard work, but of all subjects it definitely comes easier to some than to others, and that's not just my own opinion or another old wive's tale, there is actual research evidence to show that.

**Timbuk2** wrote: »

Guys, I would advise you to just forget about today's paper, and concentrate on your next exams. Hearing other people say they did well, and people posting answers you didn't get will only dishearten you.

This!

It's Friday night, it's nearly 12. Forget about the maths, go watch tv or a video or something for an hour, get a good night's sleep, and start doing a bit for the next ones tomorrow.

Killio9

i nearly cried when Boland didn't come up on honours maths paper! shes all i know!

tommycarey1

Hi. I was happy with today's paper overall. Just wondering with question 2 part b. The alpha beta one. The answer was 4 for the first part. I read the roots incorrectly so my answer was 16 while it should have been the square root of it, which was 4. Same obvious mistake for part ii. Do you think they will rape me on marks?

JamieByrne

tommycarey1 wrote: »

Hi. I was happy with today's paper overall. Just wondering with question 2 part b. The alpha beta one. The answer was 4 for the first part. I read the roots incorrectly so my answer was 16 while it should have been the square root of it, which was 4. Same obvious mistake for part ii. Do you think they will rape me on marks?

No at most you'll get 2 blunders probably 14/20 marks so not totally raped:D
Any1 else find the answers to de moivre's theorem q a bit strange???
also y de hell was arithmetic sequence in q 1??:eek: Never did dat b4!!!!!!!! Ended up writin a lettr 2 de corrector outlinin hw unfair dat q was:mad:

Cian92

It was a pretty OK paper, found question 3 to be very bitty though! Also in question 1)c)3 was sneaky. What in Gods name is an Arithmitic series? craazy!

JamieByrne

mark.oc wrote: »

Q.1 (a) k = -3, t = 9

(c)(i) -3-b
(ii) -2-2b
(iii) b = -4, c = 1, d = 6

Q.2 (a) x = 3, y = -2, z = -1

(b)(i) 4
(ii) rt20 or 2rt5

Q.3 (a) x = 4, y = 2

(b)(i) ±6
(ii) -8

(c) Didn't take them down as they were all decimals.

Q.4 (a) 47/99

(b)(i) a = -42, d = 6
(ii) 0

(c)(iii) 27230

Q.5 (a) x = 2

(c)(ii) 47

Q.6 (a) x = 4/3

(b)(i) 2/5
(ii) line

(c)(i) [LATEX](-4-2xy^3)/(2+3x^2y^2)[/LATEX]
(ii) 2x + y - 6 is the tangent.

Q.7 (b)(i) 2/(1-2cosxsinx)

(c)(ii) minimum

Q.8 (a) -(cos2x)/2 + (e^4x)/4 + c

(b) 37 units

(c)(i) ln((1+sinb)/(1+sina))
(ii) ln((1+cosa)/(1+cosb))

wow i got all them but i never wrote down the equatin of de tangent in 6 (c) (ii) bt did u need it?

imissplaytv

JamieByrne wrote: »

No at most you'll get 2 blunders probably 14/20 marks so not totally raped:D
Any1 else find the answers to de moivre's theorem q a bit strange???
also y de hell was arithmetic sequence in q 1??:eek: Never did dat b4!!!!!!!! Ended up writin a lettr 2 de corrector outlinin hw unfair dat q was:mad:

Eh that should help!!!!:D

SantryRed

Quick q. I didn't see on the alpha beta question that alpha and beta were greater than 0. So I did the question once for 4 and then again for -4. As I had it correct will I get all the marks or does working out -4 too dock me marks? Thanks.

imissplaytv

JamieByrne wrote: »

wow i got all them but i never wrote down the equatin of de tangent in 6 (c) (ii) bt did u need it?

I do hope you were a bit more careful with your spelling in English.:D

Cian92 wrote: »

It was a pretty OK paper, found question 3 to be very bitty though! Also in question 1)c)3 was sneaky. What in Gods name is an Arithmitic series? craazy!

ah, not much point in worrying about it now though, don't ya think!!!:D

Better to concentrate on Mondays' papers at this stage, I reckon!

Because kids, there's is a ****load coming down the line!!!

mahonykid

lads wise dude once told me its never as good as it seems and never as bad as it seems
......was fit to cry during paper cos i thought it was so hard but lookin back at it ,i got the same answers and made the same mistakes as most of ye so i cnt be too far off the ball !!!




also why are ye all takin the fella who posted answers as right ??? for all we know some could be wrong..all 8 questions done in 2 and a half hours.. and right on top of it.hmmm do u have contacts in the department ha :I

drumlover22

Done 5 pretty good questions, was never good at Q 3,4,5 but attempted them all the same so hopefully I'm on my way to getting a C2, maybe even higher

MollyJayne

mahonykid wrote: »

lads wise dude once told me its never as good as it seems and never as bad as it seems
......was fit to cry during paper cos i thought it was so hard but lookin back at it ,i got the same answers and made the same mistakes as most of ye so i cnt be too far off the ball !!!




also why are ye all takin the fella who posted answers as right ??? for all we know some could be wrong..all 8 questions done in 2 and a half hours.. and right on top of it.hmmm do u have contacts in the department ha :I

Because his answers fit the equations and/or make sense!
E.g. for 1. c) iii) -4, 1, and 6 fit the sequence and the equation, where a lot of people got -4, -7, -10 or something else that just fit the sequence and not the equation.
E.g. 2] I can't remember the number, but the parametric curve question. It is a line and makes sense to be, but because it said "curve", I though it must have to curve =[

See...his answers make sense, so are more than likely right!

EuropeanSon

SantryRed wrote: »

Quick q. I didn't see on the alpha beta question that alpha and beta were greater than 0. So I did the question once for 4 and then again for -4. As I had it correct will I get all the marks or does working out -4 too dock me marks? Thanks.

Just a blunder I think. -3.

**Timbuk2**

I had a dream last night that seeing as they put a series part in Q1, on paper 2 they put probability mixed with Trig and Vectors! I would probably cry

EuropeanSon

mahonykid wrote: »

lads wise dude once told me its never as good as it seems and never as bad as it seems
......was fit to cry during paper cos i thought it was so hard but lookin back at it ,i got the same answers and made the same mistakes as most of ye so i cnt be too far off the ball !!!




also why are ye all takin the fella who posted answers as right ??? for all we know some could be wrong..all 8 questions done in 2 and a half hours.. and right on top of it.hmmm do u have contacts in the department ha :I

I did all 8 in an hour and a half. It's not that difficult once you know how to do them.

mark.oc

mahonykid wrote: »

also why are ye all takin the fella who posted answers as right ??? for all we know some could be wrong..all 8 questions done in 2 and a half hours.. and right on top of it.hmmm do u have contacts in the department ha :I

No, but I can't afford anything but to have got em right. I need an A1 to fulfil the conditions of my uni offer.

EuropeanSon

mark.oc wrote: »

No, but I can't afford anything but to have got em right. I need an A1 to fulfil the conditions of my uni offer.

Same here. What is it you're going for? UCAS?

chaoticmess

mark.oc wrote: »

No, but I can't afford anything but to have got em right. I need an A1 to fulfil the conditions of my uni offer.

Ouch! What course is that for?!
I applied to UCAS and need a C3. If I needed an A1 I think I'd have died by now.... or else just failed all my other subjects!!

kieran--f

I need a c2 for uws and a b2 for heriot watt where did ye apply