***2015 LC Maths Paper 1 - Higher Level - June 5th***

DarraghF197

RoRo979 wrote: »

im the same, Section A was nice, the last part of q1 i did 16 instead of 14. The second part of the complex numbers with the W blew my mind. Percentage error and part C of the last question is all i got wrong i think.

Section B however, crazy hard imo. Never integrated a function like that. Never differentiated a function like that, One of my attemps of differentiating the
4.75sin(2pi/365)(T) was mad, so i thought right, product rule grand.
So U is 4.75 and V is sin(---) but then dv/dx involved another prouct rule where U = 2pi/654 and V was t so then U required another quotent rule which at this point i just gave up.

I've never really lookwd at integration by parts before. But I think it would have helped a load in that question with the sines. You had to just backtrack the way to get an expression that, if differentiated, would give you your original expression.

Nearly got caught with the signs there! I was multiplying one number by -1 three times on the one line haha.

YouKnowNothing

Looks like there's utter uproar and outrage on the ordinary level thread :L

Kremin

DarraghF197 wrote: »

I've never really lookwd at integration by parts before. But I think it would have helped a load in that question with the sines. You had to just backtrack the way to get an expression that, if differentiated, would give you your original expression.

Nearly got caught with the signs there! I was multiplying one number by -1 three times on the one line haha.

integration by parts is complicating things too much. To differentiate a trig function, say Cos2x, it is technically chain rule, but the rule is.. multiply the whole thing by the coefficient of x, so 2... and change the function..

Dy/dx of cosx is -sinx
so the whole thing is
-2sin2x


and it's just the same for that question, only complication is the pi and the very odd numbers, but nothing a calculator can't do !

Luke Armstrong

Did anyone use n in the complex no's (b) as n-1?

tornados2111

Does anyone know if there were any questions in which you had to differentiate twice to check if it was a max or min?

Jijsaw

YouKnowNothing wrote: »

Looks like there's utter uproar and outrage on the ordinary level thread :L

And rightly so, did you see our paper?!? :P

Lucky people with your 25 extra points *grumble grumble*

Kremin

Jijsaw wrote: »

And rightly so, did you see our paper?!? :P

Lucky people with your 25 extra points *grumble grumble*

I know im really ignorant because i'm so used to higher level, but what's so difficult about it? I heard a lot of people complaining about the patterns question btu if you fill out the table correctly it seems easy enough? Do you think maybe everyone just panicked and thought it was a lot more difficult?

Jijsaw

Kremin wrote: »

I know im really ignorant because i'm so used to higher level, but what's so difficult about it? I heard a lot of people complaining about the patterns question btu if you fill out the table correctly it seems easy enough? Do you think maybe everyone just panicked and thought it was a lot more difficult?

If you saw all of the previous papers, our paper was nothing compared to those. Generally OL questions were structured in a way that hinted the formula or what to do and they would get progressively harder however only a few of the questions on this paper give an idea of what to do and some of the questions just threw us straight into the deep end. This is obviously not good for students who would be D or low C students in maths as they wouldn't know what to do. Ordinary Level maths is meant to be a more basic, accessible and easier to approach than than HL (obviously) however the way it was layed out just made it extremely difficult for both strong and weak students to deal with.
That and no financial maths showed up :pac:

expiiplus1

Did you notice the really simple solution part of 9?
The maximum value of sin(x) is 1. You are then basically done. It was too bad I only noticed this AFTER I solved it the hard way. I also solved 8 b) directly - V(t) and V(r) are equal obviously. So manipulate them until you have r in terms of t. Differenciate, and you are done (After you calculate t when r=5000 from your original formula and sub into the derivative) Horrible but effective.

Doctorhopeful

Jijsaw wrote: »

And rightly so, did you see our paper?!? :P

Lucky people with your 25 extra points *grumble grumble*

I don't mean to be that guy, but which were the tricky questions? I looked through and it all seemed doable. People are moaning and saying they could've given the higher level paper a better attempt than the ordinary level one, but the higher level one presented more challenges in my opinion?

I understand the outrage, but there seems to be a bit of a hivemind going on. That being said, if it helps people chill and relax after maths then i'm a-ok with that!

EDIT: i see Kremin got there first, you can ignore my being obtuse!

Kremin

expiiplus1 wrote: »

Did you notice the really simple solution part of 9?
The maximum value of sin(x) is 1. You are then basically done. It was too bad I only noticed this AFTER I solved it the hard way. I also solved 8 b) directly - V(t) and V(r) are equal obviously. So manipulate them until you have r in terms of t. Differenciate, and you are done (After you calculate t when r=5000 from your original formula and sub into the derivative) Horrible but effective.

That's the beauty of maths, there's always multiple ways to do anything.

RoRo979

actually can someone tell how how to do q8, or where i went wrong

Write an equation for V(t), the volume of oil on the water, in cm3, after t minutes:

i did 4t(10^6)

The spilled oil forms a circular oil slick 1 millimetre thick.
(i) Write an equation for the volume of oil in the slick, in cm3
, when the radius is r cm.

i did .1pi(r)^2

Find the rate, in cm per minute, at which the radius of the oil slick is increasing when
the radius is 50 m

i did dr/dt = (dv/dt)(dr/dv)
dv/dt = .1pi(r)^2
dr/dv = pi(r)^2(h)

Luke Armstrong

RoRo979 wrote: »

Find the rate, in cm per minute, at which the radius of the oil slick is increasing when
the radius is 50 m

i did dr/dt = (dv/dt)(dr/dv)
dv/dt = .1pi(r)^2
dr/dv = pi(r)^2(h)

dr/dv=1/(dv/dr)

MmmPancakes

RoRo979 wrote: »

actually can someone tell how how to do q8, or where i went wrong

Write an equation for V(t), the volume of oil on the water, in cm3, after t minutes:

i did 4t(10^6)

The spilled oil forms a circular oil slick 1 millimetre thick.
(i) Write an equation for the volume of oil in the slick, in cm3
, when the radius is r cm.

i did .1pi(r)^2

Find the rate, in cm per minute, at which the radius of the oil slick is increasing when
the radius is 50 m

i did dr/dt = (dv/dt)(dr/dv)
dv/dt = .1pi(r)^2
dr/dv = pi(r)^2(h)

the 50m radius part:
http://prntscr.com/7dhn6y

The part after:
http://prntscr.com/7dhogc

dazzadazza

Anyone have a solution to the length of days question. I'm not sure if I did them right or not.

Gallagher1

This year's LC cohort honestly don't know how blessed they are getting a P1 like that. The financial maths Q honestly looked like it could appear on an Ordinary exam. I know many students will be on here thinking that today's exam was a nightmare but I have to say, if you're quite good in maths, that paper was a walk in the park.

Goes to show the result of a Department of Education that is hellbent on getting as many kids as possible to take the HL paper while keeping the failure rate constant.. lenient papers and no doubt even more lenient marking schemes!

username 2212

Still trying to find the hard question on the OL paper....

MmmPancakes

username 2212 wrote: »

Still trying to find the hard question on the OL paper....

Same :rolleyes:

Jijsaw

MmmPancakes wrote: »

Same :rolleyes:

Don't roll your eyes, various people find different levels of maths hard.
If you'd read my post on the previous page, you would have known that the structure and wording of the questions was completely changed than previous years and trigonometry which was only previously examined on Paper 2 was included in Paper 1. Not to mention the other differences I previously wrote out.
Just because you have been doing HL maths for the past 2 years you think you can roll your eyes at a paper that is obvious the majority of ordinary level students found challenging. For a lot of people who were D and weak C students, this paper completely threw them, I know people who could only do the first 2 questions because they find maths difficult and it was extremely unfair of the SEC to alter the paper so dramatically this year especially on an Ordinary Level paper, where many of the partakers obviously struggle with maths.

Fiona G

Seeing a few people on the OL thread saying they'd have done better in the HL paper?! I think that's a bit much. Their paper was challenging for OL standard yes, but I don't think ours was as ''easy'' as the media are making it out to be, and definitely not easier than the OL paper by a long shot!!

Kremin

Guys after talking to other people who did OL, I can see where they're coming from... one question asked them to find g(x) and it presented like 2x-3g(x)=x^2+x+6.... obviously it wanted them to divide the quadratic by the linear function but a lot of them didn't catch that because the terminology was too difficult and unseen before at OL...

I don't think it's fair to say the HL paper was too easy though? It's such a risk for some people doing HL and someone in my exam centre was almost pulling out his hair during that exam and couldnt even attempt the last 3 questions....

The marking schemes for BOTH papers will be adjusted so the stats are in line with previous years... they aren't going to jump from a 1% fail rate to 50%. end of rant.

You have to consider some HL students who dropped may have found that OL paper a breeze, but the people who struggle with maths, and yes there are some of them, would have found the terminology confusing and unnecessarily complicated.

skippy1977

I'd sum it up like this. Of course the Higher Level Paper was more difficult than the Ordinary and if people found the Ordinary hard they would have definitely struggled with the Higher Level Paper.

The Higher wasn't simple and the Ordinary wasn't impossible BUT the Higher Level Paper was below the standard it should have been. This is to ensure that the 1/3 of extra people who are doing the subject (and who realistically aren't able) get through. The Financial Maths question was ridiculously easy and of ordinary level standard (if not in content). As was a number of other parts but it was also quite tricky in places). It will be marked accordingly and a similar amount of people will get A's, B's and C's etc as always.
The Ordinary Level Paper was a good bit above the standard it should have been. There is no doubt about that. It's easy for a Higher Level student to look at the Paper and say 'well where is the hard parts??' but that's why you are in higher level. Remember that the majority of students who are taking the Ordinary Level struggle with Maths, at the very least in the higher order thinking sections. They had some very quiet simple stuff also but alot of the paper was presented in a way unfamiliar to them. Again the marking scheme will be adjusted and the same amount of people will get A's, B's and C's. Don't be a bit surprised to see a marking scheme that gives 15 marks for 7(a), 15 marks for 7(b) 10 for 7(c), 10 for 7 (d)...all doable...and 20 marks for the (f-h).

So at it's level the Ordinary Paper was much trickier...but obviously an easier Paper overall. My advice to everyone is to nail your Paper 2 whatever the level. You are all competing on the curve and it's not how easy or difficult it is....it's how easy or difficult it is relative to other students in the hall!

Luke Armstrong

How were you suppose to do the last part of Q9? I integrated between 184 and 0, and divided by 184 but I heard some people saying there's a formula?

student625

Can someone please post a link to solutions for pp1? thank you

MmmPancakes

Luke Armstrong wrote: »

How were you suppose to do the last part of Q9? I integrated between 184 and 0, and divided by 184 but I heard some people saying there's a formula?

Average value formula: 1/(b-a) x (integral of f(x) with the boundaries a -> b)

Kremin

Luke Armstrong wrote: »

How were you suppose to do the last part of Q9? I integrated between 184 and 0, and divided by 184 but I heard some people saying there's a formula?

Well you integrate and multiply by 1/b-a, which is just 1/184.

YouKnowNothing

Luke Armstrong wrote: »

How were you suppose to do the last part of Q9? I integrated between 184 and 0, and divided by 184 but I heard some people saying there's a formula?

That is the formula! Average value

Kremin

YouKnowNothing wrote: »

That is the formula! Average value

yeah either divide by difference in upper and lower limit or multiple by 1/difference.

MmmPancakes

Jijsaw wrote: »

Don't roll your eyes, various people find different levels of maths hard.
If you'd read my post on the previous page, you would have known that the structure and wording of the questions was completely changed than previous years and trigonometry which was only previously examined on Paper 2 was included in Paper 1. Not to mention the other differences I previously wrote out.
Just because you have been doing HL maths for the past 2 years you think you can roll your eyes at a paper that is obvious the majority of ordinary level students found challenging. For a lot of people who were D and weak C students, this paper completely threw them, I know people who could only do the first 2 questions because they find maths difficult and it was extremely unfair of the SEC to alter the paper so dramatically this year especially on an Ordinary Level paper, where many of the partakers obviously struggle with maths.

my bad, feeling a bit bitter/skeptical towards people in the OL thread saying we had it easy and that they would have passed higher but failed ordinary.

Luke Armstrong

I think that the last 3 questions were of a similar standard to previous years but the first 6 were way too easy, that Q2 how could anyone not have been able to do that??