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***2015 LC Maths Paper 2 - Higher Level - June 8th***

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    #152
    qweerty
    Closed Accounts Posts: 367 ✭✭qweerty


    First, I feel very guilty about diverting attention away from Skippy1977's brilliantly-detailed solution on previous page. Check it out in case you've missed it!
    dalta5billion wrote: »
    Also as an applied maths student, I think I was unfairly advantaged in that golf ball projectile question. We knew instantly to let the height=0 to find the time of landing, and "horizontal speed" is a term that would confuse others.
    Kremin wrote: »
    Ye thats what i was thinking, I didn't even realise anyone who did applied maths would be at an advantage. Like, someone said s=ut would help but cmon, it travels for 4 seconds at 32 m/s, that's jc science at best.

    Just on the point about AM. That I can think, the projectile question in today's P2 is the farthest Maths has ever encroached on Applied Math's turf. I don't think there's any doubt that AM (and to a much lesser extent, Physics) students were at an advantage: that's not to say others were disadvantaged, but AM-ers would instinctively have known how to get TOF and wouldn't have been in any way confused by the fact that there was a horizontal "speed" that stayed constant.

    While perhaps 'finding the TOF' should have been made a separate part before finding the angle of inclination, my biggest problem is with the mention of the horizontal component of velocity. I think perhaps there could have been a short blurb about splitting a velocity into its perpendicular components, and also think the information should have been phrased as, The motion of the ball in the horizontal direction is at a constant speed of X. A tad wordy, but it reduces some potential misunderstandings. Also, should've been horizontal velocity, not speed.

    I wonder, and this is only a hypothesis that will probably be proved wrong, whether it's possible that they're testing the waters to see if they can incorporate more Applied Maths content with a view to removing it as a subject. There is obviously much more to projectile motion than is in that question, and then there are the other topics too, but AM starts to become untenable if Maths examines the same skills as it (albeit, in that question, to a much lesser extent). Mechanics modules covering the same topics as AM are options for ALevel maths.


  • Options
    #153
    MmmPancakes
    Registered Users Posts: 712 ✭✭✭MmmPancakes


    qweerty wrote: »
    First, I feel very guilty about diverting attention away from Skippy1977's brilliantly-detailed solution on previous page. Check it out in case you've missed it!





    Just on the point about AM. That I can think, the projectile question in today's P2 is the farthest Maths has ever encroached on Applied Math's turf. I don't think there's any doubt that AM (and to a much lesser extent, Physics) students were at an advantage: that's not to say others were disadvantaged, but AM-ers would instinctively have known how to get TOF and wouldn't have been in any way confused by the fact that there was a horizontal "speed" that stayed constant.

    While perhaps 'finding the TOF' should have been made a separate part before finding the angle of inclination, my biggest problem is with the mention of the horizontal component of velocity. I think perhaps there could have been a short blurb about splitting a velocity into its perpendicular components, and also think the information should have been phrased as, The motion of the ball in the horizontal direction is at a constant speed of X. A tad wordy, but it reduces some potential misunderstandings. Also, should've been horizontal velocity, not speed.

    I wonder, and this is only a hypothesis that will probably be proved wrong, whether it's possible that they're testing the waters to see if they can incorporate more Applied Maths content with a view to removing it as a subject. There is obviously much more to projectile motion than is in that question, and then there are the other topics too, but AM starts to become untenable if Maths examines the same skills as it (albeit, in that question, to a much lesser extent). Mechanics modules covering the same topics as AM are options for ALevel maths.
    Bring back vectors! :pac:


  • Options
    #154
    dalta5billion
    Registered Users Posts: 1,034 ✭✭✭dalta5billion


    qweerty wrote: »
    Just on the point about AM. That I can think, the projectile question in today's P2 is the farthest Maths has ever encroached on Applied Math's turf. I don't think there's any doubt that AM (and to a much lesser extent, Physics) students were at an advantage: that's not to say others were disadvantaged, but AM-ers would instinctively have known how to get TOF and wouldn't have been in any way confused by the fact that there was a horizontal "speed" that stayed constant.

    While perhaps 'finding the TOF' should have been made a separate part before finding the angle of inclination, my biggest problem is with the mention of the horizontal component of velocity. I think perhaps there could have been a short blurb about splitting a velocity into its perpendicular components, and also think the information should have been phrased as, The motion of the ball in the horizontal direction is at a constant speed of X. A tad wordy, but it reduces some potential misunderstandings. Also, should've been horizontal velocity, not speed.

    I wonder, and this is only a hypothesis that will probably be proved wrong, whether it's possible that they're testing the waters to see if they can incorporate more Applied Maths content with a view to removing it as a subject. There is obviously much more to projectile motion than is in that question, and then there are the other topics too, but AM starts to become untenable if Maths examines the same skills as it (albeit, in that question, to a much lesser extent). Mechanics modules covering the same topics as AM are options for ALevel maths.

    Excellently put.

    The new guy setting the AM paper is pretty much fighting for the subject's survival, trying to make the paper more challenging and relevant (aka more project mathsy), and causing great angst in the process.

    While I'd support a future branching out of maths into different strands, this ridiculous limbo for current students in which the examiners mix and match and bell curve the hell out of everything is really undesirable.


  • Options
    #155
    qweerty
    Closed Accounts Posts: 367 ✭✭qweerty


    MmmPancakes wrote: »
    Bring back vectors! pacman.gif

    Mmmm, Vectors. I'd sooner take back matrices, tbh. Probably more fun at this level.

    dalta5billion wrote: »
    Excellently put.

    The new guy setting the AM paper is pretty much fighting for the subject's survival, trying to make the paper more challenging and relevant (aka more project mathsy), and causing great angst in the process.

    While I'd support a future branching out of maths into different strands, this ridiculous limbo for current students in which the examiners mix and match and bell curve the hell out of everything is really undesirable.

    On that point, people might be interested in a post by ThePhysicsTeacher on his blog, Thinkforyourself.ie: http://thinkforyourself.ie/2014/11/28/a-response-to-the-recent-ncca-discussion-document-on-applied-maths/. It links to a "discussion document" about Applied Maths and gives his opinion.

    For my money, AM is brilliant, but too intimidating and too liable to be rote-learnt (I rarely did a question from before 2000, but people I've met in college have done literally the last thirty year's worth). Get rid of Hydro, RBM and Statics (which no one does), leaving just kinematics, add some other topics (perhaps a meatier calculus section), lay out papers somewhat (!) similarly to Project Maths and make a proper fcuking syllabus!

    On rereading my previous post, I realise...
    dalta5billion wrote: »
    Also as an applied maths student, I think I was unfairly advantaged in that golf ball projectile question. We knew instantly to let the height=0 to find the time of landing, and "horizontal speed" is a term that would confuse others.
    qweerty wrote: »
    AM-ers would instinctively have known how to get TOF and wouldn't have been in any way confused by the fact that there was a horizontal "speed" that stayed constant.

    ...that I merely made the exact same points as you! :D

    What I had also meant to say was that one shouldn't underestimate the extent to which familiarity helps with these questions. (Although, familiarity can have it's downsides: I was initially differentiating the function to find Vy at TOF!)


  • Options
    #156
    theRB
    Registered Users Posts: 209 ✭✭theRB


    skippy1977 wrote: »
    Did a bit of an exploration of a method using slopes rather than perpendicular and it becomes a bit unwieldy!!

    Definitely works but requires a bit more thinking...and there is less accuracy due to having to round decimals...now this answer not fully fleshed out but does go most of the way to show how to get one of the correct answers 0.75...interestingly when I took the (negative version of tan) I got the 13.8...that some others mentioned (but which isn't a valid solution).

    I have the method I would use underneath.

    You can actually do it without using any formula at all. If you just do tan inverse of the two slopes, you get the angles they make with the x-axis. If you combine these, half it and then deduct the angle of l2 with the x-axis, you get the angle of the bisector with the x-axis. Then you get tan of this and multiply by 6 to get k. Then repeat with the other angle. Can be done really fast on a calculator as long as you don't go rounding things off like I did, which obviously left me with something slightly off.


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    #157
    Kremin
    Registered Users Posts: 944 ✭✭✭Kremin


    qweerty wrote: »
    Mmmm, Vectors. I'd sooner take back matrices, tbh. Probably more fun at this level.




    On that point, people might be interested in a post by ThePhysicsTeacher on his blog, Thinkforyourself.ie: http://thinkforyourself.ie/2014/11/28/a-response-to-the-recent-ncca-discussion-document-on-applied-maths/. It links to a "discussion document" about Applied Maths and gives his opinion.

    For my money, AM is brilliant, but too intimidating and too liable to be rote-learnt (I rarely did a question from before 2000, but people I've met in college have done literally the last thirty year's worth). Get rid of Hydro, RBM and Statics (which no one does), leaving just kinematics, add some other topics (perhaps a meatier calculus section), lay out papers somewhat (!) similarly to Project Maths and make a proper fcuking syllabus!

    On rereading my previous post, I realise...





    ...that I merely made the exact same points as you! :D

    What I had also meant to say was that one shouldn't underestimate the extent to which familiarity helps with these questions. (Although, familiarity can have it's downsides: I was initially differentiating the function to find Vy at TOF!)

    Rigid Body motion is one of my favourite questions, ha.

    Also about the projectiles question today, there was quite a few questions on integrations that were much more applied mathsy, I remember doing one where it gave you acceleration and eventually when you integrated you'd have a displacement equation that matched with ut+1/2at^2 .

    Anyway maybe we were at an advantage, but even if we were, it was only a small one. It shouldn't have been to difficult to know to let y=0 to find where it intersects an axis.


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    #158
    qweerty
    Closed Accounts Posts: 367 ✭✭qweerty


    Kremin wrote: »
    Rigid Body motion is one of my favourite questions, ha.

    Also about the projectiles question today, there was quite a few questions on integrations that were much more applied mathsy, I remember doing one where it gave you acceleration and eventually when you integrated you'd have a displacement equation that matched with ut+1/2at^2 .

    Anyway maybe we were at an advantage, but even if we were, it was only a small one. It shouldn't have been to difficult to know to let y=0 to find where it intersects an axis.

    Iirc, which I'm pretty sure I do :p, RBM was the seventh most popular topic in the last three chief examiners' reports. Imagine where it would be if it didn't have the proof! I always liked SHM and Statics, if I'm honest.

    What you say about integration isn't necessarily applied mathsy, tho. Several of the 'express a in terms of x,y,z' questions at junior cert result in one of the equations of motion and Ord LC maths used to have a differentiation question that would start with the equation you mention; obviously neither of those is applied mathsy. I don't know the type of question you're referring to, but the problem isn't that the maths deals with applications, but instead that the questions perhaps too closely resemble content in another subject.

    I'd say it matters not if you didn't do AM but are an A student. But I imagine a C AM student would have got it but that a C Maths student will likely not have. Like I said, being familiar with the concepts frees up your mind to solve the problem.

    Maths all over. I retreat till Applied Maths comes around!


    Edit: I realise that, because of the difference in cohort size and ability, the C-C comparison isn’t entirely valid. But the point still stands that average students, merely by having done AM rather than having been any good at it, may outperform on that question.


  • Options
    #159
    Kerrypike
    Registered Users Posts: 6 ✭Kerrypike


    For the circle question my whole method was right for all the parts, however I very stupidest forgot to fill in the lengths as ratios in part 2 and that made the rest of my subsequent answers wrong, what does this mean? Will the examiner mark me down on just that part or will it be carried right through despite my method being right?


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    #160
    randylonghorn
    Moderators, Education Moderators Posts: 29,509 Mod ✭✭✭✭randylonghorn


    The general rule is that you only get penalised for an error once.


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    #161
    Kremin
    Registered Users Posts: 944 ✭✭✭Kremin


    qweerty wrote: »
    Iirc, which I'm pretty sure I do :p, RBM was the seventh most popular topic in the last three chief examiners' reports. Imagine where it would be if it didn't have the proof! I always liked SHM and Statics, if I'm honest.

    What you say about integration isn't necessarily applied mathsy, tho. Several of the 'express a in terms of x,y,z' questions at junior cert result in one of the equations of motion and Ord LC maths used to have a differentiation question that would start with the equation you mention; obviously neither of those is applied mathsy. I don't know the type of question you're referring to, but the problem isn't that the maths deals with applications, but instead that the questions perhaps too closely resemble content in another subject.

    I'd say it matters not if you didn't do AM but are an A student. But I imagine a C AM student would have got it but that a C Maths student will likely not have. Like I said, being familiar with the concepts frees up your mind to solve the problem.

    Maths all over. I retreat till Applied Maths comes around!


    Edit: I realise that, because of the difference in cohort size and ability, the C-C comparison isn’t entirely valid. But the point still stands that average students, merely by having done AM rather than having been any good at it, may outperform on that question.
    Thinking about it overnight I see where you're coming from.


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    #162
    fongcy
    Registered Users Posts: 34 ✭fongcy


    i wonder what does it mean by
    you can only be penalised an error once?
    does that mean for one question or the whole exam?
    please explain
    .


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    #163
    BrianBoru00
    Registered Users Posts: 1,035 ✭✭✭BrianBoru00


    As a simple example.
    (a) if a number z =2(x) +(y) and x=4 and y=2 what is the value of z ? [10 marks]
    (b) What is 2z + 5 ? [10 marks]

    So the answer to a is 2(4) +(2) = 10
    but suppose you made a mistake and got 9

    The answer to part b should be 2(10) + 5 = 25 which would get you the full ten marks.
    If however you used the wrong answer from part a and answered
    2( 9 ) +5 = 23 instead of 25 then you would still get full marks (10 out of 10) for part b.
    The reason is because the mistake was made in (a) and you ve been penalised there for it.


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    #164
    Frigating
    Registered Users Posts: 249 ✭✭Frigating


    The whole exam. If you get a wrong answer and have to use it for another part of the question (say part a and b) you'll be marked for part b based on your answer for a. As long as your method is right, it's just that value (the answer from a) is wrong, you'll get full marks for b. (though you'll lose marks for part a)


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    #165
    fongcy
    Registered Users Posts: 34 ✭fongcy


    right thanks guys!
    understand abit!
    howabout if i get (a) right and then (b) right but did c wrong and used the ans from c to do d?

    and does this apply for each long question?
    cheers.


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    #166
    BrianBoru00
    Registered Users Posts: 1,035 ✭✭✭BrianBoru00


    Yep - same thing would apply in general .
    i.e. d is corrected based on the answer YOU use from c


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    #167
    riskshamam
    Registered Users Posts: 55 ✭✭riskshamam


    Just thought I'd throw this up to see if anyone has any solutions/thoughts for the two higher level maths papers. I would be particularly interested in seeing solutions for the probability question!


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    #168
    qweerty
    Closed Accounts Posts: 367 ✭✭qweerty


    riskshamam wrote: »
    Just thought I'd throw this up to see if anyone has any solutions/thoughts for the two higher level maths papers. I would be particularly interested in seeing solutions for the probability question!

    Solutions to both papers <redacted>. BUT...there are multiple mistakes, some minor, some major.


    Way too many mistakes tbh. Not queerty's fault, don't kick him (this time :pac:) - R.


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    #169
    Luke Armstrong
    Registered Users Posts: 31 ✭Luke Armstrong


    Q1 is horribly wrong along with the Sin3x one


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    #170
    skippy1977
    Registered Users Posts: 284 ✭✭skippy1977


    qweerty wrote: »
    Solutions to both papers <redacted>. They stress there may be mistakes. I've seen two minor ones across the four lc maths papers.

    Plenty right in this. Probably an A or B in fairness but:

    Mistakes in 1(c), 2(b) and (c), 3(c) 5(c) 7(c) Q8 (b) (c) (d) (e)

    Don't meant to be too critical but it has branding of a website selling products and should be held to a slightly higher standard. Q2 (b) and (c) is way off.


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    #171
    riskshamam
    Registered Users Posts: 55 ✭✭riskshamam


    qweerty wrote: »
    Solutions to both papers <redacted>. They stress there may be mistakes. I've seen two minor ones across the four lc maths papers.

    Thanks, but ya they made a few bad mistakes and didnt manage the tougher parts at all. Ah welll


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    #172
    qweerty
    Closed Accounts Posts: 367 ✭✭qweerty


    Luke Armstrong wrote: »
    Q1 is horribly wrong along with the Sin3x one
    skippy1977 wrote: »
    Plenty right in this. Probably an A or B in fairness but:

    Mistakes in 1(c), 2(b) and (c), 3(c) 5(c) 7(c) Q8 (b) (c) (d) (e)

    Don't meant to be too critical but it has branding of a website selling products and should be held to a slightly higher standard. Q2 (b) and (c) is way off.

    Just to distance myself from it... They're done by an online grinds company (with which I have no connection). Don't think one is allowed to give names.

    Edit: Jesus, I hadn't actually looked through the attempt at Higher P2, but it's a disaster.


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    #173
    skippy1977
    Registered Users Posts: 284 ✭✭skippy1977


    qweerty wrote: »
    Just to distance myself from it... They're done by an online grinds company (with which I have no connection). Don't think one is allowed to give names.

    They sell "samples with questions and solutions in detail for all the likely questions to occur on this years exam"...mmm

    I hate this kind of stuff. I've mentioned here before students I know returning from Grinds companies with 'predictions' of what might be coming up. They had notes with 'Teacher X's' prediction for Q4 or 5'...


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    #174
    Luke Armstrong
    Registered Users Posts: 31 ✭Luke Armstrong


    Wait for Q1 you were supposed to put W or L right? not 1,1


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    #175
    qweerty
    Closed Accounts Posts: 367 ✭✭qweerty


    From the Ordinary:

    upload.png

    Person probably under a lot of pressure, but I still feel they should have done better.


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    #176
    lostatsea
    Registered Users Posts: 320 ✭✭lostatsea


    qweerty wrote: »
    Solutions to both papers <redacted>. They stress there may be mistakes. I've seen two minor ones across the four lc maths papers.

    My advise is that nobody should touch these solutions. They certainly were not done by a teacher.


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    #177
    simplyno1
    Registered Users Posts: 25 ✭simplyno1


    Skippy would you mind saying the answer to 2. b, 2.c, 7.c, 7.d? you dont have to do it out, just an explanation of some sort.


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    #178
    RoRo979
    Registered Users Posts: 476 ✭✭RoRo979


    Luke Armstrong wrote: »
    Wait for Q1 you were supposed to put W or L right? not 1,1

    ye i feckin shat myself when i seen it, there is alot of mistakes that got me worried. Tbh i think you should just delete the link because so much mistakes in it will only make people feel worse.


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    #179
    Kremin
    Registered Users Posts: 944 ✭✭✭Kremin


    lostatsea wrote: »
    My advise is that nobody should touch these solutions. They certainly were not done by a teacher.

    I saw a lot of errors in paper 1.. for example straight away he did the ball dropping question wrong by counting 2 twice when it is dropped from that height.

    Oh god, just looked at paper 2.. the probability one where it asked you to fill in the table, am I the only person who wrote W or L in each box, not the combination of the results??
    I didnt think thats what they wanted because it said for example 1 on the left and 1 on the top -__-


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    #180
    skippy1977
    Registered Users Posts: 284 ✭✭skippy1977


    simplyno1 wrote: »
    Skippy would you mind saying the answer to 2. b, 2.c, 7.c, 7.d? you dont have to do it out, just an explanation of some sort.

    eh...haha okay now I'm putting myself on the chopping block!! Give me a sec and I'll see if I can dig them out!!


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    #181
    qweerty
    Closed Accounts Posts: 367 ✭✭qweerty


    Okay, okay, there's probably a good argument for me to remove the link. Problem is it's been reposted by a few!

    Just to totally clarify, I have no connection with the person or company who produced the "solutions"; I just saw the link for it on someone's FB.


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