Maths HL P 1 - aftermath

SantryRed

What about saying it was an Asymptote? Same thing?

zam

I said in Q6 that the graph was "increasing". Do you think i'll get attempt marks??

Ashashi

I said the curve was "n-shaped" cause I was clueless :P

pn7xjrqy6fhta1

if you write something down nd cross it out again nd if sum of it is right wud u get 3 attempt marks for having some of it write

NumberZeroNine

johnmcdnl wrote: »

asking sequences and series in question 1 is a disgrace.. not everyone studies that question...

True, I don't do it and I had to pretty much guesstimate how to do it.

-4, 1, 5 anyone?

zam

Analia Acidic Wolf wrote: »

if you write something down nd cross it out again nd if sum of it is right wud u get 3 attempt marks for having some of it write

Yes! As far as I'm aware

UglyFuc

for 1c were u supposed to divide the two factors in and slove the two remainders or sub in 2 and -1 and then solve

i did both. spent ages and roughly ended up with 4 similar equations with mixed signs

worked ous as -2-2b and b-3

mark.oc

Ashashi wrote: »

Not really, usually, you don't need to explain, you just get (any no)^2 > 0.

I'd imagine it'll be the same this year. I know they give out marks for practically everything, but I can't imagine explaining to the examiner that
1 > 0 will gain you marks.

validusername

zam wrote: »

I said in Q6 that the graph was "increasing". Do you think i'll get attempt marks??

I sure hope so! I said that too.

monaghanman10

monaghanman10 wrote: »

did nybody else use induction to prove 4c part ii

I did! Thanking my lucky stars they said 'or otherwise' because I didn't see the link with part i at all...

Ashashi

mark.oc wrote: »

I'd imagine it'll be the same this year. I know they give out marks for practically everything, but I can't imagine explaining to the examiner that
1 > 0 will gain you marks.

Then just elaving it as 16p^2 +1 > 0 would get full marks? cause to me it appeared that I got stuck, so I explained to be sure.

Can't take marks away for being precise.

leavingcert

zam wrote: »

I said in Q6 that the graph was "increasing". Do you think i'll get attempt marks??

I said the same!

EuropeanSon

No. Unless they give attempt marks for any answer at all. The answer, I believe, was that it was a straight line, as the slope wasn't variable.

zoom!

Mixed reactions it seems. Soom thought it was ridiculously hard and others thought it was super easy. I thought it was grand tbh. I think with a bit of study for paper 2 i could get that c1 i've been after and maybe even with some more look a b

leavingcert

KealanOCarroll wrote: »

whole stack of people in my year did that too....i knew lookin at it that it didn say integers it said consecutive terms but i hadnt a nothion so i jus took a stab at callin them B=B, C= B+1 and D = C+ 1....hopin for attempt marks!

I just said (n-1)-1

zam

validusername wrote: »

I sure hope so! I said that too.

At least the question is probably only worth 5 marks. Even if we didn't get it it's not too big a deal! Still, it's still technically correct, just not what they were looking for.

dazco

I think that was the best exam I've ever done in my life, did all 8 questions and everything work out for me. Q4, usually my best question was challenging but I got it in the end......so happy.....

**Timbuk2**

How did you prove that the summation of r squared was n/6(n+1)(2n+1) - I was trying for ages to get that, and couldn't. I got most of the other questions though - I was happy with it overall. Nervous about P2 though - not as much choice, and a compulsory 'Option' question (it's not really 'option'al)

EuropeanSon

zam wrote: »

At least the question is probably only worth 5 marks. Even if we didn't get it it's not too big a deal! Still, it's still technically correct, just not what they were looking for.

No it isn't. Increasing is relative to where you are looking from. Saying "X increases as Y increases" would be a more accurate answer.

monaghanman10

for 4c (iii) used the formula r squared = n/6 (n+1)(2n+1)

SantryRed

Wish they'd tell us the answers now :pac:

dazco

**Timbuk2** wrote: »

How did you prove that the summation of r squared was n/6(n+1)(2n+1) - I was trying for ages to get that, and couldn't.

I isolated r^2 from c(1) then subbed that into the Sigma bit, split it up, wrote out the first and last terms till they started to cancel then tidied it up and it work out perfectly

**Timbuk2**

dazco wrote: »

I isolated r^2 from c(1) then subbed that into the Sigma bit, split it up, wrote out the first and last terms till they started to cancel then tidied it up and it work out perfectly

Nice thinking - well done!

I attempted telescoping it out but it didn't work out great. I'm hoping for an attempt mark for that particular bit!

Gaga OhLaLa

how did anyone do Q2 part c(ii)?

NumberZeroNine

Anyone want to give me a guesstimation on the amount of marks docked for Question 8; (b) below?

Correct limits chosen
Correct formula formed for the area A = 0I1 y.dx + 0I1 y.dx
Correctly Intregrated A = [3x4-16x3+18x2]01 +[3x4-16x3+18x2]13
Correctly sub'd in A = [5] - [0] + [-27] - [5]


However, here I got the lenght of -27 before factoring in the 5, thus I got;
A = 5 +27 - 5
A = 27 square units


EDIT: Following Note;
Tried putting in sub and sup text, thats what the bold numbers are, powers and limits, sorry it's unclear.


Please let me know how you think that will be hit, I'm on 280 out of 300 before that blunder.

kieran--f

I thought it was hard
Will i get much attempt marks for 8 part b if I got the interval fom 0 to 3 instead of getting 0 to 1 then 1 to 3 and adding I was kicking myself afterwards

**Timbuk2**

**Timbuk2** wrote: »

How did you prove that the summation of r squared was n/6(n+1)(2n+1) - I was trying for ages to get that, and couldn't. I got most of the other questions though - I was happy with it overall. Nervous about P2 though - not as much choice, and a compulsory 'Option' question (it's not really 'option'al)

I went with 'otherwise' and proved it by induction.

NumberZeroNine

kieran--f wrote: »

I thought it was hard

Will i get much attempt marks for 8 part b if I got the interval fom 0 to 3 instead of getting 0 to 1 then 1 to 3 and adding I was kicking myself afterwards

Big blunder, i'd say you're only going to be getting marks for knowing how to integrate it and substitute in properly

EuropeanSon

kieran--f wrote: »

I thought it was hard
Will i get much attempt marks for 8 part b if I got the interval fom 0 to 3 instead of getting 0 to 1 then 1 to 3 and adding I was kicking myself afterwards

Most likely you'll just lose 3 for a blunder.

DancingQueen:)

I said the graph was decreasing, I hadn't got a breeze and because it was less than one I guessed that. Definitely happy though, had a look at the answers that were posted and got a lot of the same answers, so here's hoping we're both right! I hadn't covered arithmetic sequences in class so though that was a little unfair as it was in Q1 but probably wasn't worth too much.