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Maths HL Paper 2

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  • Closed Accounts Posts: 32 psychoduck


    foxpoint1 wrote: »
    i got the same and its right for 6a. 1/6

    what did ye get for 7b) part 3? i got 23/48

    I got 39/40


  • Registered Users, Registered Users 2 Posts: 2,819 ✭✭✭EuropeanSon


    JerCotter7 wrote: »
    But AB = OC. Not the same line. So your way is just the exact same.

    Also technically CB =/= A
    |CB| = |A|
    There we go. That hit the nail on the head, I was pondering that one myself, thanks!


  • Registered Users Posts: 814 ✭✭✭JerCotter7


    There we go. That hit the nail on the head, I was pondering that one myself, thanks!

    Haha took me a while to realize what I was doing wrong until I looked at the test paper again and saw the |AQ|.


  • Registered Users Posts: 285 ✭✭Ashashi


    4 was sound apart from c ii and ciii....
    q5 raped me:(

    Q5 involved a lot of working out, and noticing things. Glad I got it, made me feel good, then Q4 appeared.... :(


  • Closed Accounts Posts: 19 foxpoint1


    psychoduck wrote: »
    I got 39/40

    actually nevermind..i wrote down a different answer in the exam..just realised there.
    did you find the prob of 2 then 3 and then add them?


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  • Closed Accounts Posts: 32 psychoduck


    foxpoint1 wrote: »
    actually nevermind..i wrote down a different answer in the exam..just realised there.
    did you find the prob of 2 then 3 and then add them?

    nope, 1 - prob of 2, because at least 2 = opposite to none


  • Closed Accounts Posts: 834 ✭✭✭Reillyman


    psychoduck wrote: »
    how did ye get 2/7 for 6a)?
    I got 1/6, because 4/10 x 5/12

    Yeah I know, stupid mistake.

    I meant to go;

    [latex]\frac{red}{total} \times \frac{red}{total}

    = \frac{4}{10} \times \frac{5}{12}[/latex]

    But instead I put;

    [latex]\frac{red}{total} \times \frac{red}{yellow}[/latex]

    Anyone know if I'll get any attempt marks, had a diagram done too?


  • Closed Accounts Posts: 32 psychoduck


    Reillyman wrote: »
    Yeah I know, stupid mistake.

    I meant to go;

    [latex]\frac{red}{total} \times \frac{red}{total}

    = \frac{4}{10} \times \frac{5}{12}[/latex]

    But instead I put;

    [latex]\frac{red}{total} \times \frac{red}{yellow}[/latex]

    Anyone know if I'll get any attempt marks, had a diagram done too?

    Sounds like something I would have done :D Well you'll get at least 5 points for red/total, i reckon


  • Closed Accounts Posts: 19 foxpoint1


    yeah you should get 5.
    how many marks would you say i got in the LaMb if i filled in un+2 and un+1 and factorised it at the end..i ran out of time..didnt quite "prove" anything,but on the way..


  • Moderators, Education Moderators, Motoring & Transport Moderators Posts: 7,395 Mod ✭✭✭✭**Timbuk2**


    When I subbed in 1/2 for x in Question 8 C, I didn't get the right answer for sin^2(1/2). What should I have done? Did it need to be changed to radians or something?


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  • Closed Accounts Posts: 834 ✭✭✭Reillyman


    Here's the Q.8(b)

    (i)[latex] y=9-x^2 [/latex]

    When [latex]x=p[/latex], [latex]y=9-p^2[/latex]

    Area [latex]=2p(9-p^2)[/latex]

    [latex]=18p-2p^3[/latex]


    (ii) Area [latex]=18p-2p^3[/latex]

    [latex]\frac{dA}{dp} = 18-6p^2 [/latex]

    [latex] 18-6p^2=0[/latex]

    [latex] 6p^2=18 [/latex]

    [latex]p^2=3[/latex]

    [latex]p=\sqrt3 [/latex]

    Max area [latex]= 18(\sqrt3)-2(\sqrt3)^3 [/latex]

    [latex]=18(\sqrt3)-6(\sqrt3) [/latex]

    [latex]=12\sqrt3 [/latex]


  • Moderators, Education Moderators, Motoring & Transport Moderators Posts: 7,395 Mod ✭✭✭✭**Timbuk2**


    Cool I got that! I always doubt myself when the answer turns to surds :o

    *PS remember for full marks you need to do the second derivative, and test for max, even if you only get one valid solution for p!


  • Closed Accounts Posts: 24 karen-xxxxx


    5) mostly proofs or showing....didnt get the C part out, got as far as Cos3x = (3^.5)Sin3x = 0 ???????????


    um i put cos3x under sin3x so i had tan3x = 1/3^.5


  • Closed Accounts Posts: 834 ✭✭✭Reillyman


    Cool I got that! I always doubt myself when the answer turns to surds :o

    *PS remember for full marks you need to do the second derivative, and test for max, even if you only get one valid solution for p!

    Yep done that!:D


  • Registered Users, Registered Users 2 Posts: 2,819 ✭✭✭EuropeanSon


    I wish every exam was maths...


  • Users Awaiting Email Confirmation Posts: 114 ✭✭UglyFuc


    Reillyman wrote: »
    Anyone else get these answers?

    1.(b)(ii) [latex] k=-17, k=-47[/latex]


    how did you get two answers? i got plus 17 so i said it was +and-17


  • Registered Users Posts: 427 ✭✭Keogg



    did anyone do question 9?

    *high fives for doing question 9*

    I was actually wondering about this - as the majority here seem to be doing question 8 ... Question 9 is actualy SO simple it's unbelievable. It's called further probability but it's actually way easier than the probability question in sectionA itself!!
    It was a dream - think I actually messed up on part a) but b) and c) were so simple :) aahhh succes...

    Really good paper overall- skipped the two trig questions and 6 and 7 looked easier.. Not sure whether I'd have done better in 5 or 7 really, but I don't care anymore :D


  • Moderators, Education Moderators, Motoring & Transport Moderators Posts: 7,395 Mod ✭✭✭✭**Timbuk2**


    I wish every exam was maths...

    After Irish and French, I have Physics, Accounting and Applied Maths, so it's quite mathsy for me from then on :)

    I agree though. You have to admit that studying maths is much more 'fun' than studying for other subjects. I'd much rather do 50 maths sums that have to learn off an essay (uhh writing and rewriting, regurgitating etc.)


  • Registered Users Posts: 427 ✭✭Keogg


    UglyFuc wrote: »
    how did you get two answers? i got plus 17 so i said it was +and-17

    When I got to the modulus equalling whatever it was, I squared both sides to get a quadratic - one of the answers ends up as 17, but you need a second :) when in doubt, square


  • Closed Accounts Posts: 16 Trackmedown


    thought the paper was oook couldve been better but couldve been a lot worse!!
    got totally stumped on Q4! my mind went blank couldnt even get the a part! thought the c part on the option (Q8) was lovely to my suprise :)

    oh did anybody get 6 times more likely for Q6(c) ???
    oh and i used decimals to solve 5(a) and the second part of b ....is that ok to do or did i like just through away loads of marks? :confused:


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  • Registered Users, Registered Users 2 Posts: 2,819 ✭✭✭EuropeanSon


    After Irish and French, I have Physics, Accounting and Applied Maths, so it's quite mathsy for me from then on :)

    I agree though. You have to admit that studying maths is much more 'fun' than studying for other subjects. I'd much rather do 50 maths sums that have to learn off an essay (uhh writing and rewriting, regurgitating etc.)
    I've got History, Irish, and German this week. Hateful. Next week is better, with Accounting and Chemistry, which are just piss easy maths with a bit of theory I can easily remember, and my favourite, Applied Maths.


  • Closed Accounts Posts: 5 Loucol


    mahonykid wrote: »
    awh man i got 36


    yeah so did!


  • Users Awaiting Email Confirmation Posts: 114 ✭✭UglyFuc


    Keogg wrote: »
    When I got to the modulus equalling whatever it was, I squared both sides to get a quadratic - one of the answers ends up as 17, but you need a second :) when in doubt, square

    but it was the distance between the center point and the line wasnt it? you just fill in the values let it equal to 3 which was the radius, cross multiply and you get k?


  • Registered Users, Registered Users 2 Posts: 2,819 ✭✭✭EuropeanSon


    thought the paper was oook couldve been better but couldve been a lot worse!!
    got totally stumped on Q4! my mind went blank couldnt even get the a part! thought the c part on the option (Q8) was lovely to my suprise :)

    oh did anybody get 6 times more likely for Q6(c) ???
    oh and i used decimals to solve 5(a) and the second part of b ....is that ok to do or did i like just through away loads of marks? :confused:
    If it worked, it should be grand, unless it specifically stated to use trig. As for 6(c), that's the right answer.


  • Registered Users Posts: 427 ✭✭Keogg


    question 9
    a)0.6826
    b)0.003
    0.202P
    0.561
    c) 69 and 91
    my dads a maths teacher so these answred have been verified:)

    only difference was part c) - I used the x-bar +/- 1.96 times sigma and it your answers, then used the other formula wth sigma over root n instead- that's what my maths teacher said was right when i showed her the paper anyway ... But I have them both down without crossing out the first one, so if you're rigth, so am I :D


  • Closed Accounts Posts: 176 ✭✭monaghanman10


    heres hoping anyway


  • Registered Users Posts: 595 ✭✭✭Roro4Brit


    I did my LC in 2002 but I always like to give the Maths papers a stab every year and see how I get on! Have yet to fail one yet :P

    I know, I know....weirdo or what. Anyhow this year I don't know anybody doing the LC - anyone any idea where I can get my hands on the papers online - preferably paper II?

    Congrats to all and I hope the hard work paid off!


  • Registered Users Posts: 427 ✭✭Keogg


    UglyFuc wrote: »
    but it was the distance between the center point and the line wasnt it? you just fill in the values let it equal to 3 which was the radius, cross multiply and you get k?

    I'm not sure, all this extra maths instea of Irish is melting my head :P
    well with the perpendicular distance formula with the modulus I squared when I had my modulus with k equal to the radius, then I squared and then cross multplied and simplified... I think


  • Closed Accounts Posts: 834 ✭✭✭Reillyman


    UglyFuc wrote: »
    how did you get two answers? i got plus 17 so i said it was +and-17

    My last few lines went like this;

    [latex]\frac{|3(4)+4(5)+k|}{\sqrt{3^2+4^2}} = 3[/latex]

    [latex]|32+k|=15[/latex]

    [latex]-32-k=15 [/latex]

    [latex]k=-47[/latex]

    or

    [latex]32+k=15[/latex]

    [latex]k=-17[/latex]

    not sure if that's the correct metod of evaluating absolute values or not but that's what I did.


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  • Registered Users Posts: 814 ✭✭✭JerCotter7


    Roro4Brit wrote: »
    I did my LC in 2002 but I always like to give the Maths papers a stab every year and see how I get on! Have yet to fail one yet :P

    I know, I know....weirdo or what. Anyhow this year I don't know anybody doing the LC - anyone any idea where I can get my hands on the papers online - preferably paper II?

    Congrats to all and I hope the hard work paid off!

    examinations.ie?


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