Maths HL P1 & 2 2017

EireLemon

Do you all know your P1 proofs for HL maths? I'm not too sure on them but I might go over them tomorrow morning

daraghwal

EireLemon wrote: »

Do you all know your P1 proofs for HL maths? I'm not too sure on them but I might go over them tomorrow morning

Does anyone have a definitive list?

wanderer100

EireLemon wrote: »

Do you all know your P1 proofs for HL maths? I'm not too sure on them but I might go over them tomorrow morning

I hope they leave all that proof nonsense for Paper 2 tbh. The De Moivre theorem proof and the amortisation one is a mess. The prove root 2 is irrational one would be fine though

thetalker

wanderer100 wrote: »

I hope they leave all that proof nonsense for Paper 2 tbh. The De Moivre theorem proof and the amortisation one is a mess. The prove root 2 is irrational one would be fine though

The de moivre one is fine if you already understand proof by induction, I haven't looked at the amortisation yet though. Kinda don't wanna.

I think the proofs come up in p1 and the trig stuff in p2, could be wrong though.

wanderer100

thetalker wrote: »

The de moivre one is fine if you already understand proof by induction, I haven't looked at the amortisation yet though. Kinda don't wanna.

I think the proofs come up in p1 and the trig stuff in p2, could be wrong though.

Induction is the one topic i've completely avoided this year. My teacher only spent 3 classes on it and my grinds teacher is adamant nothing on induction will come up this year. I'll stab my neck with my compass if I see the words induction on tomorrows paper

BadBannana

Wasn't there a thing last year where no proofs came up? I'm too tired to remember properly...

If I'm right it means they'll be lashing them on tomorrow

daraghwal

BadBannana wrote: »

Wasn't there a thing last year where no proofs came up? I'm too tired to remember properly...

If I'm right it means they'll be lashing them on tomorrow

No proofs on either paper, no constructions (one sort of but not an actual construction) and there was a proof by induction divisibility proof on paper 1

EireLemon

They tend to rotate induction & financial maths, financial maths is due up this year. I'd love a few constructions, if the square root of 2 comes up tomorrow I'll be delighted.

Xgracie

Yeah I haven't a clue how to do the de moivres one and could start the ammortisation but not finish it, let's hope they don't come up with cry if I lost 15 marks over a proof lol

Take Your Pants Off

Would we need to know how to prove the sum of geometric series and sequence without induction ?.
Also prove that the second difference is 2a for a quafratic sequence.

EireLemon

Will anyone else be using a pencil even though it says you're not allowed for maths? I make a decent few mistakes so I like to keep it neat

A97

EireLemon wrote: »

Will anyone else be using a pencil even though it says you're not allowed for maths? I make a decent few mistakes so I like to keep it neat

I don't think pencil is recommended, but people do use it every year and aren't marked down for it. The main concerns are that it could fade or possibly smudge. If it makes you feel better, just use a reasonably heavy pencil (HB or B would probably be best) and I doubt it would be a problem.

One warning about using pencil though. I know that teachers and examiners have noted in the past that people are more likely to rub out answers that they think are wrong, which often means that the candidate misses out on attempt marks. Try not to remove anything you write. Put a line through it so it remains readable. You might have been right or close to correct without realising.

For Paper I, know these proofs:

De Moivre for Natural Numbers
Induction
The infinite sum formula on the bottom of page 22 of the tables
Amortisation
Root 2 is irrational

And for Paper II:

cos^2(A) + sin^2(A) = 1
Sine Rule
Cosine Rule
The other trigonometric ones that should be in your book
Theorems 11, 12 and 13
And also know all of the constructions (However, it seems quite unlikely that they will ask a Junior Cert but they're easy enough to revise. Be certain that you know the ones that are Leaving Cert only.)

One more thing, if you forget how to find the centroid of a triangle from the Paper II construction, it is shown on page 52 of the tables. It shows the joining of one corner of the triangle to the midpoint of the opposite side. Do that for two sides and you've found it.

BadBannana

You're my hero

carefulnowted

WTF was that paper

BadBannana

Last two questions were a disaster. I'm so angry with myself.

VG31

That was much harder than previous paper ones. Even the financial maths which is usually doable was very difficult. I was hoping for a H4 in maths. I reckon I got 40-45% in that paper so there's not much hope of that now.

The only one I got fully correct (I think) was the sequences and series question.

Mr Rhode Island Red

Was OK up until question 8. Made a bit of a hames of financial maths and left most of question 9 blank.

Feeling neutral enough tbh

BadBannana

Seemed like an easy paper to me bar the financial maths. Realised I made a stupid error on that question about the tide on the walk. That's 110 marks out the window

Manufan123

Was alright, short Q's were OK. Q9 just did the graph. Would you get marks is you integrated the sum of a geometric series in the financial q?

padraigmck

Mr Rhode Island Red wrote: »

Was OK up until question 8. Made a bit of a hames of financial maths and left most of question 9 blank.

Feeling neutral enough tbh

For Question 8 part (b), I couldn't do it, fine the €A amount... it didn't give us any time period so how were we supposed to do it?

jogd1234

padraigmck wrote: »

For Question 8 part (b), I couldn't do it, fine the €A amount... it didn't give us any time period so how were we supposed to do it?

Think I got 66 months for it, if that's the one you're talking about

nanook5

Loved it. Thought it was great

ciara18

jogd1234 wrote: »

Think I got 66 months for it, if that's the one you're talking about

I got 66 months too!! Thought I did that wrong that's made me very happy! Messed up question 9 though, what was trig doing on paper 1 at all?

daraghwal

jogd1234 wrote: »

Think I got 66 months for it, if that's the one you're talking about

66 months is right, our teacher got it too. Remember that if everyone found certain parts of questions hard, then those parts of the questions will be worth less than you would think to keep in line with the bell curve

wanderer100

Can someone tell me what is up with Trigonometry being on Paper 1!! First they put poetry on English P1 and now this.

Is there not a clear structure anywhere of what can be asked on either papers or do we just have to make presumptions from past papers.

carefulnowted

I got ~3250 or something like that for the amount of money saved at the end of Q8. Sound familiar to anyone?

ciara18

carefulnowted wrote: »

I got ~3250 or something like that for the amount of money saved at the end of Q8. Sound familiar to anyone?

Yes! I was sure that was wrong, seemed too large a difference!

Manufan123

Anyone remember their answers for the sequence q?

padraigmck

Manufan123 wrote: »

Anyone remember their answers for the sequence q?

Day 13 for the part (a).....

carefulnowted

I think I got 16 + 8 root 2 for the second bit of the sequences. And day 13 for the first bit.

ciara18

Manufan123 wrote: »

Anyone remember their answers for the sequence q?

for the second part it was something like 16±the square root of something, I think

daraghwal

https://www.examinations.ie/tmp/1497029290_3232988.pdf

Could someone do out 4 (a) to put my mind at ease? Also what did people get for a and b on question 6 and what did people get for the end of question 9 (c)

I know post mortems aren't good but it's just to put my mind at ease. Thanks in advance!

I think I got 10 for 4 (a) for some reason

Nyctolust

I swore to myself I wouldn't leave anything blank but the last two questions were barely even started (couldn't even get the table in the financial maths question to work out) and I did end up leaving some other blanks. Couldn't get a single bit of the amortisation proof either because I don't even remember doing it in class at any point. I'm really bloody frustrated with myself because I was counting on getting an okay mark in P1 since I normally find P2 much harder, and I could tell this paper wasn't even bad, I'm just really stupid.

Haven't even decided which Irish essays to learn this weekend. Gah

Telo123

Anyone get like 32 euro for the weekly repayment amount?

daraghwal

Telo123 wrote: »

Anyone get like 32 euro for the weekly repayment amount?

Got something like that. Could be 36 but definitely in the 30s.

hasdanta

Telo123 wrote: »

Anyone get like 32 euro for the weekly repayment amount?

I think I got like €31.16 or something along does lines

Manufan123

daraghwal wrote: »

Got something like that. Could be 36 but definitely in the 30s.

36 sounds familiar

carefulnowted

I got €33 point something. I think varying answers there could be attributed to rounding/not rounding the interest rate, so hopefully we won't lose many marks.

tibetan452309

carefulnowted wrote: »

I got €33 point something. I think varying answers there could be attributed to rounding/not rounding the interest rate, so hopefully we won't lose many marks.

Got that as well. Normally they don't deduct marks for rounding off/not rounding off unless they specified.

Did you get 66 months for the amortisation one?

carefulnowted

Yep. I don't think Q8 went too badly for me, but Q9 and Q7 were another story. I couldn't figure out when the populations would be the same at all.

jogd1234

daraghwal wrote: »

https://www.examinations.ie/tmp/1497029290_3232988.pdf

Could someone do out 4 (a) to put my mind at ease? Also what did people get for a and b on question 6 and what did people get for the end of question 9 (c)

I know post mortems aren't good but it's just to put my mind at ease. Thanks in advance!

I think I got 10 for 4 (a) for some reason

For 4(a) I got 13, the answer is 12.47 or something but rounds up. Use tn=ar*n-1 with r= 0.45.

For 6(b) I got something like 0.4968 I think.

For 9(c) I think I got 13:26 and 15:42, my method wasn't very mathsy but I think those are the answers.

thetalker

So angry about the amortisation proof, had no clue what do do.
Also what was up with that financial table, I got €125 euro as the monthly payment so how on earth is 41 euro the interest to pay??
Am I just being stupid or something.
Also that tide q was a nightmare.

One more thing, I didn't realize |w| was the radius and wasted that Q. arrrgh.

Hope I ace p2 otherwise I'm screwed.

ciara18

thetalker wrote: »

So angry about the amortisation proof, had no clue what do do.
Also what was up with that financial table, I got €125 euro as the monthly payment so how on earth is 41 euro the interest to pay??
Am I just being stupid or something.
Also that tide q was a nightmare.

One more thing, I didn't realize |w| was the radius and wasted that Q. arrrgh.

Hope I ace p2 otherwise I'm screwed.

The interest was from remaining lump sum left over each time, not the €125!

VG31

thetalker wrote: »

So angry about the amortisation proof, had no clue what do do.

I didn't even know that proof existed. I thought all the proofs were on Paper 2.

thetalker wrote: »

So angry about the amortisation proof, had no clue what do do.
Also what was up with that financial table, I got €125 euro as the monthly payment so how on earth is 41 euro the interest to pay??
Am I just being stupid or something.
Also that tide q was a nightmare.

I got €125 as well. Did anyone else get that? It seemed like a simple question at the start but it was actually really confusing.

How were you supposed to get a and b in Q9? I had absolutely no idea.

Telo123

thetalker wrote: »

So angry about the amortisation proof, had no clue what do do.
Also what was up with that financial table, I got €125 euro as the monthly payment so how on earth is 41 euro the interest to pay??
Am I just being stupid or something.
Also that tide q was a nightmare.

One more thing, I didn't realize |w| was the radius and wasted that Q. arrrgh.

Hope I ace p2 otherwise I'm screwed.

I thought it was the modulus of the complex number

blueee

Telo123 wrote: »

thetalker wrote: »

So angry about the amortisation proof, had no clue what do do.
Also what was up with that financial table, I got €125 euro as the monthly payment so how on earth is 41 euro the interest to pay??
Am I just being stupid or something.
Also that tide q was a nightmare.

One more thing, I didn't realize |w| was the radius and wasted that Q. arrrgh.

Hope I ace p2 otherwise I'm screwed.

I thought it was the modulus of the complex number

Yeah, I thought that was the modulus too!?

thetalker

ciara18 wrote: »

The interest was from remaining lump sum left over each time, not the €125!

Fuuuuuu-

How are we supposed to know that. Arrrgh

Edit: I see it now, I just wish I had before...

Monaghan_98

Telo123 wrote: »

I thought it was the modulus of the complex number

I think that |w| means the modulus! What did you get for t in that answer?

thetalker

blueee wrote: »

Yeah, I thought that was the modulus too!?

Same thing, I took it literally as in

|r(cos30°+isin30°)| equals 3
So then {r(cos30+isin30)}^2 equals 3^2

You can see how wrong that is though

If you did r equals 3 for w that's right

Which means
w = 3(cos30+isin30)

carefulnowted

I got t = -6 + 0i

wanderer100

carefulnowted wrote: »

I got t = -6 + 0i

I got t = +6 +0i