**HL Maths P2 Before/After

ehshup

finality wrote: »

Lol! yes I do, can't believe I wrote "one of each colour is green", hahaha.

My way of doing that seems crazy now, but it was my first instinct on how to do it. Your way is much less complicated

well fair play for getting that probability right, i can't get my head around getting probabilities when there's a bunch of constraints like that! It took me a long long time to do that question right

mcpaddington

Chuchoter wrote: »

How do we time it? IS there any defined structure?

12.5 minutes each for questions 1 - 6. 37.5 minutes each for 7 and 8.

finality

ehshup wrote: »

well fair play for getting that probability right, i can't get my head around getting probabilities when there's a bunch of constraints like that! It took me a long long time to do that question right

I struggle with them myself. Took me ages to work that question out too.

DepoProvera

finality wrote: »

I don't think it matters as you're just showing the correlation? Could be wrong there though.

I dunno, my notes say "If there is no obvious cause and effect between the two variables, then it does not matter which we call X and which we call Y. On the other hand if either i) we have control over one variable and just want to observe the other e.g the amount of fertiliser applied to plants and their heights ii) one variable is suspected to cause a change in the other iii)we want to use one variable to estimate the value of the other variable then we should let X(the independent or explanatory variable) be the first variable, and Y(the dependent or response variable) be the second variable"

So basically it means that cause= X axis effect=Y axis

mcpaddington

If anyone has their mock papers could you post a scan of it up?

DepoProvera

mcpaddington wrote: »

If anyone has their mock papers could you post a scan of it up?

Yeah I'd love if anyone had the one that isn't DEB..

Chuchoter

mcpaddington wrote: »

12.5 minutes each for questions 1 - 6. 37.5 minutes each for 7 and 8.

12.5 minutes...thats a bitch

ehshup

in reality though, 8 and 9 definitely do not take that long

FaoiSin

I have a feeling I'll be pushed for time "/

Canard

I wont be able to make a dent in Q8 so yeah, thatll get me some time... :L

Epsi

Chuchoter wrote: »

12.5 minutes...thats a bitch

The first five questions are relatively quick to do in my opinion. The only questions that take a considerable length of time are 7 and 8.

mcpaddington

DepoProvera wrote: »

Yeah I'd love if anyone had the one that isn't DEB..

I have mine, the only thing is I'm not sure what company it is. Q8 is about a group of transition years putting up a green house or something. Oh and it's in Irish.

DepoProvera

Nah, that's different than mine. Damn, man, project maths in Irish. Well that would be fun..

mcpaddington

DepoProvera wrote: »

Nah, that's different than mine. Damn, man, project maths in Irish. Well that would be fun..

Yea it's some craic all right :pac:

We get the English paper too but our answers must be written in Irish.

Superbus

DepoProvera wrote: »

Could an example of proof by contradiction be from paper 1? To prove a rational function has no turning points: differentiate, let f'(x)=0 and it gives a false statement... Or does it have to be from Paper 2?

If anyone knows the answer to this, I would also like to know.

paddyhes

Does anyone know if we have to do our answers in the grid spaces they provide us with?
I never have enough space.
Could you do the exam in a booklet like paper 1 and just hand it up with it?

ChemHickey

ehshup wrote: »

By the way, can anyone explain to me the given solution for 9A part (a), I've never had to use the 95% confidence interval in that way.?
http://www.ncca.ie/en/Curriculum_and_Assessment/Post-Primary_Education/Project_Maths/Project_Maths_Pre-leaving_Exam_Papers_Feb_2010/P_Maths_LC_HL_Paper_2_with_solutions.pdf

It's used this way when working, once again, with the central limit theorem. The standard deviation is divided by the margin of error due to the fact that it is of such great numbers. It's unlikely to appear as it is apparently not on our course but it still could appear as an empirical rule type question where we use 2 instead of 1.96

mcpaddington

paddyhes wrote: »

Does anyone know if we have to do our answers in the grid spaces they provide us with?
I never have enough space.
Could you do the exam in a booklet like paper 1 and just hand it up with it?

Yea you can do it in a booklet.

MathsManiac

paddyhes wrote: »

Does anyone know if we have to do our answers in the grid spaces they provide us with?
I never have enough space.
Could you do the exam in a booklet like paper 1 and just hand it up with it?

The superintendent won't give you one of the ordinary booklets, but you can ask for the smaller "extra paper" booklets (the 4 page ones). You really should start off in the booklet and just go on to extra paper if you run out of room.

If you don't do it in the booklet, you could easily end up skipping a part of a quesion by mistake. You won't do that if you're writing in the booklet, because you'll notice the gap.

Anyway, do you really want your work to be marked by someone who's p***ed off at you for making his or her life difficult?

mcpaddington

Here's the ncca Project Maths Paper 2 for 2012: http://www.examinations.ie/schools/Project_Math_Phase_1_P2_Higher_Level.pdf

Damn just realised this is the one we already had.

Need some new material to do.

emmamurphy233

Superbus wrote: »

If anyone knows the answer to this, I would also like to know.

It can be anything as long as it properly illustrates proof by contradiction!

emmamurphy233

ehshup wrote: »

By the way, can anyone explain to me the given solution for 9A part (a), I've never had to use the 95% confidence interval in that way.?
http://www.ncca.ie/en/Curriculum_and_Assessment/Post-Primary_Education/Project_Maths/Project_Maths_Pre-leaving_Exam_Papers_Feb_2010/P_Maths_LC_HL_Paper_2_with_solutions.pdf

That's definitely not on our course, don't worry.

paddyhes

What constructions and definitions do we need to know?

ehshup

mcpaddington wrote: »

Yea you can do it in a booklet.

Technically we're not allowed unless we run out of space, the project maths people actually said our marks may be forfeited if you don't answer in the provided space, but to be honest, I can't picture them doing that.

ehshup

ChemHickey wrote: »

It's used this way when working, once again, with the central limit theorem. The standard deviation is divided by the margin of error due to the fact that it is of such great numbers. It's unlikely to appear as it is apparently not on our course but it still could appear as an empirical rule type question where we use 2 instead of 1.96

could you explain why you multiply the standard deviation by margin of error. Even if it came up as empirical, empirical and central limit theorem would mean that if you took multiple samples of 40 and found the mean, the means' distribution would approximate a normal distribution. So is standard deviation of a sample mean multiplied by the percentage error (given number of members of the sample set) the standard deviation of the normal distribution created by charting various samples? lol i'm pretty confused
EDIT: it's ok I found my answer at http://stattrek.com/estimation/confidence-interval-mean.aspx
i just had never seen that formula at all, now i know thank god!

hamal

ehshup wrote: »

could you explain why you multiply the standard deviation by margin of error. Even if it came up as empirical, empirical and central limit theorem would mean that if you took multiple samples of 40 and found the mean, the means' distribution would approximate a normal distribution. So is standard deviation of a sample mean multiplied by the percentage error (given number of members of the sample set) the standard deviation of the normal distribution created by charting various samples? lol i'm pretty confused
EDIT: it's ok I found my answer at http://stattrek.com/estimation/confidence-interval-mean.aspx
i just had never seen that formula at all, now i know thank god!

you my friend may aswell be speaking a different language

finality

ehshup wrote: »

could you explain why you multiply the standard deviation by margin of error. Even if it came up as empirical, empirical and central limit theorem would mean that if you took multiple samples of 40 and found the mean, the means' distribution would approximate a normal distribution. So is standard deviation of a sample mean multiplied by the percentage error (given number of members of the sample set) the standard deviation of the normal distribution created by charting various samples? lol i'm pretty confused
EDIT: it's ok I found my answer at http://stattrek.com/estimation/confidence-interval-mean.aspx
i just had never seen that formula at all, now i know thank god!

I'm pretty sure the majority of that isn't on our course. We just need to know that when you split a population into lots of groups of size n, the standard deviation of each group is approximately equal to the standard deviation of the population divided by root n.

ehshup

hamal wrote: »

you my friend may aswell be speaking a different language

haha sorry i have the hang of it now no worries!

paddyhes

anybody know where we can find solutions to our mocks?

Mista

emmamurphy233 wrote: »

It can be anything as long as it properly illustrates proof by contradiction!

Explanation:
To prove something by contradiction, we assume that what we want to prove is not true and then we show that the consequences of this are not possible.

Example:

Prove by contradiction that there are no positive integer solutions to the equation x^2 - y^2 = 1

Assume the contradiction of this, i.e. there are positive integer solutions.

Proof:

x^2 - y^2 = 1
(x-y)(x+y) = 1

(x-y) and (x+y) are both = -1
OR
(x-y) and (x+y) are both = +1


x - y = 1
x + y = 1
2x = 2
x = 1
y = 0

(1,0)

OR
x - y = -1
x + y = 1
2x = -2
x = -1
y = 0

(-1,0)

_______________________________________________________________

Neither of these are solutions are both positive integers.

.'. contradicting our asumption that the are no positive integer solutions to x^2 - y^2 = 1

Hope it helps