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Maths Paper II (HL) - How was it?

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    #92
    ~Candy~
    Closed Accounts Posts: 435 ✭✭~Candy~


    galway.gaa wrote: »
    no i drew a right angled tringle cos we already had cos15/17. i think i got 4/15 or something like that

    so you got tan and then divided by 2 right ?


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    #93
    VinnyTGM
    Registered Users Posts: 827 ✭✭✭VinnyTGM


    It was alright, got Q. 1,2,3 out mostly and bits of 4,5.
    Q.8 was a disaster.


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    #94
    Zonda999
    Registered Users Posts: 5,533 ✭✭✭Zonda999


    galway.gaa wrote: »
    no i drew a right angled tringle cos we already had cos15/17. i think i got 4/15 or something like that

    The triangle in the question wasnt right angled though so areyou sure you're able to do that? If so i've lost out on a couple of marks!:(

    Tried using some tan 2A formula on pg9 but it didnt work out fully!:mad:


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    #95
    ~Candy~
    Closed Accounts Posts: 435 ✭✭~Candy~


    Dmullar wrote: »
    Yep. Really can't remember what answer I got though.

    i couldn't ither,,,
    thank god someone was with me at least :)


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    #96
    [Deleted User]
    Posts: 4,630 ✭✭✭ [Deleted User]


    ~Candy~ wrote: »
    did any1 use the tan2a formula to get the tan A/2 thingy

    Yah, that's what I used. I got 4/15 or something like that. It was right, anyway.


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    #97
    galway.gaa
    Closed Accounts Posts: 145 ✭✭galway.gaa


    Zonda999 wrote: »
    The triangle in the question wasnt right angled though so areyou sure you're able to do that? If so i've lost out on a couple of marks!:(

    Tried using some tan 2A formula on pg9 but it didnt work out fully!:mad:
    i got the same answer as people who used the tan2a formula. it doesnt matter if the original is not right angled. the cos15/17 is only a ratio not a meassurement


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    #98
    Prowetod
    Registered Users Posts: 521 ✭✭✭Prowetod


    How did q6 go for people?

    I should have done q2 instead of q6, hopefully it wont cost me too much!


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    #99
    Fince
    Registered Users Posts: 412 ✭✭Fince


    -JammyDodger- wrote: »
    Yah, that's what I used. I got 4/15 or something like that. It was right, anyway.

    how're you so sure?


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    #100
    SugoiHito
    Banned (with Prison Access) Posts: 62 ✭✭SugoiHito


    ~Candy~ wrote: »
    did any1 use the tan2a formula to get the tan A/2 thingy
    Yes,i did!


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    #101
    galway.gaa
    Closed Accounts Posts: 145 ✭✭galway.gaa


    Q7(a) im not sure about it for some reason, i got 3.1


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    #102
    munchie14
    Registered Users Posts: 114 ✭✭munchie14


    question 2 c i
    did every 1 get oddish numbers like -+(5root2)divide by 4 or something for k

    sorry or was that k in question 1 b ii



    was slopes of question 3b ii) -3 and 1divided by 3

    question 5 c
    can any remember the angle at b for the triangle for cos rule


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    #103
    UnknownSpecies
    Registered Users Posts: 3,183 ✭✭✭UnknownSpecies


    galway.gaa wrote: »
    Q7(a) im not sure about it for some reason, i got 3.1

    yup simple question, 3.1 was what i got too!


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    #104
    NerdPantzz
    Closed Accounts Posts: 35 ✭NerdPantzz


    yep DCU requires maths as do most univeristies!


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    #105
    Claypigeon
    Closed Accounts Posts: 660 ✭✭✭Claypigeon


    NerdPantzz wrote: »
    yep DCU requires maths as do most univeristies!

    There is no "university requirement" look at your course requirements, also note that DCU is not an NUI


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    #106
    NerdPantzz
    Closed Accounts Posts: 35 ✭NerdPantzz


    yeah I checked.. It requires a D3
    Here's hoping I passed anyway!


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    #107
    Des23
    Closed Accounts Posts: 287 ✭✭Des23


    -JammyDodger- wrote: »
    Yah, that's what I used. I got 4/15 or something like that. It was right, anyway.

    I don't know,
    cos^-1 15/17 = 28.0724
    28.0724/2= 14.036
    tan 14.036 = 1/4

    Which is the answer that I got using the Tan2a formula aswell...
    I could be wrong, but I felt it worked out nicely.


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    #108
    [Deleted User]
    Posts: 4,630 ✭✭✭ [Deleted User]


    Des23 wrote: »
    I don't know,
    cos^-1 15/17 = 28.0724
    28.0724/2= 14.036
    tan 14.036 = 1/4

    Which is the answer that I got using the Tan2a formula aswell...

    I'm pretty sure 4/15 is right.

    sin^2(A) = 1 - cos^2(A)
    sin(A) = sqrt(1-225/289)
    sin(A) = 8/17

    tan(A) = sin(A)/cos(A)
    tan(A) = (8/17)/(15/17)
    tan(A) = 8/15

    tan(A/2) = 4/15

    I could be wrong, but the maths seems to work out, anyway.


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    #109
    NerdPantzz
    Closed Accounts Posts: 35 ✭NerdPantzz


    GA361 wrote: »

    F * U * C * K
    That was a disaster . . . . . . .. . . . . .After having done so well in P1:mad::mad::mad::mad::mad::mad::mad::mad::mad::mad::mad::mad::mad::mad::mad:

    God Damnit!!!!!!!!!!!!!!!!!!!!!!!!!!!
    my thoughts exactly.


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    #110
    Prowetod
    Registered Users Posts: 521 ✭✭✭Prowetod


    Des23 wrote: »
    I don't know,
    cos^-1 15/17 = 28.0724
    28.0724/2= 14.036
    tan 14.036 = 1/4

    Which is the answer that I got using the Tan2a formula aswell...
    I could be wrong, but I felt it worked out nicely.

    I got 1/4, but I used the Cos(2A)=1-tan^2(A/2)/1+than^(A/2), which I presume is right cos you were using CosA in the first part of q.

    Anyone have answers for 6?


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    #111
    Fince
    Registered Users Posts: 412 ✭✭Fince


    in that question, i no it said not to evaluate A, but if u did just to check your answer, the correct answer is a quarter


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    #112
    xOxSinéadxOx
    Registered Users Posts: 2,604 ✭✭✭xOxSinéadxOx


    I wish this thread would just fade into oblivion and stop reminding me how **** I did!


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    #113
    Prowetod
    Registered Users Posts: 521 ✭✭✭Prowetod


    What did people get for 6a and 6b


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    #114
    Des23
    Closed Accounts Posts: 287 ✭✭Des23


    Fince wrote: »
    in that question, i no it said not to evaluate A, but if u did just to check your answer, the correct answer is a quarter

    Yeah I didn't evaluate A, I was just using the figures to make my point.
    eoccork wrote: »
    What did people get for 6a and 6b

    I can't remember what I got for a, but I got 12 for b which seemed reasonable.

    part c, made my soul die a little.. I got 5/70 for the last part but I'm not prepared to say that that is the correct answer. I ended up doing an extra question because I really wasn't happy with Q6.

    I thought it was a nice to have the stats and difference equations in 1 question, made it easier on the brain trying to switch between probability and more regular maths. But I suppose that if they always do that then even less people will end up doing actual probability..


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    #115
    galway.gaa
    Closed Accounts Posts: 145 ✭✭galway.gaa


    Fince wrote: »
    in that question, i no it said not to evaluate A, but if u did just to check your answer, the correct answer is a quarter
    i got 8/15 which is the same as jammy dodge. i did it a different way though. as i said before i did it using a right angled triangle and im pretty sure thats right. if it came out right doin it 2 different ways like:eek:


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    #116
    Acid_Violet
    Closed Accounts Posts: 1,295 ✭✭✭Acid_Violet


    Bye bye A1.....


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    #117
    Prowetod
    Registered Users Posts: 521 ✭✭✭Prowetod


    Des23 wrote: »
    I can't remember what I got for a, but I got 12 for b which seemed reasonable.

    K thanks, I got n=4 for 6(b)(iii)


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    #118
    Fringe
    Registered Users Posts: 1,082 ✭✭✭Fringe


    -JammyDodger- wrote: »
    tan(A/2) = 4/15

    I could be wrong, but the maths seems to work out, anyway.

    tan(A/2) doesn't equal (tanA)/2


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    #119
    [Deleted User]
    Posts: 4,630 ✭✭✭ [Deleted User]


    Fringe wrote: »
    tan(A/2) doesn't equal (tanA)/2

    Didn't realise that's what I'd written in my comment. That's why it's not a good idea to solve a problem as you're typing it...

    I just flicked back through my paper and I'd written 8/15 as my answer on the side of the page (I never worked out tan(A/2), just tan(A) - mustn't have seen the (A/2) bit when I was doing the question - so there goes 7 or so marks).

    And the answer seems to be 1/4. At least that's the answer you get from rearranging the cos(2A) formula.


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    #120
    NerdPantzz
    Closed Accounts Posts: 35 ✭NerdPantzz


    why is everyone trying to explain questions from the exam? we never have to do maths again!!!! Focus on upcoming subjects rather that worrying about things that cant be changed


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    #121
    galway.gaa
    Closed Accounts Posts: 145 ✭✭galway.gaa


    NerdPantzz wrote: »
    why is everyone trying to explain questions from the exam? we never have to do maths again!!!! Focus on upcoming subjects rather that worrying about things that cant be changed
    cause maths is class and its fun to know what you got:D


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