This discussion is now closed.

Check out other Related discussions

Mathematics AEA Discussion Thread (Timings Passed)

Scroll to see replies

Doh, I missed this thread. My question-by-question ramblings are here.

Sam: Pretty sure the cos of ABC was 1/3.
Also fairly sure p=9, q=9/8.

Reply 21

Totally Tom

DFranklin

For the logs question, I get a cubic (3x^3-50x^2+184x-192 = 0) with roots x=2, x = 8/3, x = 12. But only x=12 doesn't involve taking the log of something negative. Curious as to how people did it - I thought solving the cubic was pretty hard for only 7 marks.

bugger, I got those solutions through solving the cubic but then i didn't think to check that they were all valid. **** **** ****.

Reply 22

bballer4life

im horrible at vectors tbh
but i think i got something like cos x= -(1/3)
not sure if it was right though

i hated the last 2 questions.
i havent done c3 in a year, and c4 in bout 6 months, guess i should of revised them

Reply 23

Cities

How did people prove 7b)?

I used quite a convoluted method and I'm sure there is an easier way to find it.

Reply 24

sam1990sam

DFranklin

Sam: I have no idea what you're talking about.

The cosine of angle ABC in exercise 7
I somehow found a negative value.

Reply 25

Totally Tom

sam1990sam

The cosine of angle ABC in exercise 7
I somehow found a negative value.

it was 1/3 so you've buggered up there but you might have taken different vectors when doing your dot product, so they are going in different directions and hence the angle. the obtuse angle will be negative.

Reply 26

bballer4life

does any1 know what the grade boundaries are for a pass, merit and distinction?

Reply 27

spex

I was about to cry when i saw that question which required you to integrate between the line AB and the curve, to get that wierd expression with 2/e(arccos(1/e) but i ****ing rejoiced when i got it in the end :biggrin:

The first question i think i got - the max sum was 8100? I differentiated the sum to get that, but you could have easily done it another way.

The next question i took a wierd approach to. I found the general solution of the DE which i got as y= A(x+2)^2/(x+1) or something. But i couldn't do the first part with the tangent for some reason so then i couldn't find the particular solution. I should still pick up some marks on the second part though :smile:

The next question i found ghastly.
simplified sin(x+60)sin(x-60) to something with .25 cos^2 - .75 sin^2 or something, then i eventually ended up with the (2 - sqrt 3) part in the first part multiplied by cos^x . I couldn't figure out what to do from then on so i flopped that.

Question 4 was messy but i killed it.

Question 5 was a bit dogdy, for the first part i saw that log p*log p = 2log p so i factorised, and got log p=0 and log p = 2, so p = 9 The first one of these gets you a dodgy answer so i used the latter. and got q=9/8. I couldn't see where 7 marks came from here. For the next part i got 12 and 2. as solutions.

I got the first parts of 6 easy enough. But the graph sketches were well dodgy and confused me for ages. A check on autograph shows my first one was alright, just missing the horizontal asymptote (i swear that's not in the core maths spec...) And my second one was the same grah translated a bit.

I didn't even attempt the last part of that question because it relied on the graphs, which i wasn't even sure were right.

Then the vectors Q. I got the first 3 parts with difficulty. I had to self flaggelate when i got home after realising i got stuck because i said -7*-4 = -28, and making another stoopid mistake like that with the other scalar product. (2 negatives do NOT make a negative) Luckily i corrected it in time but then i didn't have enough time to finish the last parts. So i just drew a few diagrams in a vain attempt at some marks. Overall i think i'll get a merit. Not bad because it means i'll make my warwick offer, but i still think my exam technique let me down. I could have gotten the distinction and the S in step 1 if i was a bit faster and kept a cool head. When i saw the clock only had half an hour left i started fretting for some reason and got hardly any work done.

Reply 28

apel

How did you do question 6 part 2. with the ff(x) couldn't do it so couldn't draw graphs

Reply 29

Cities

bballer4life

does any1 know what the grade boundaries are for a pass, merit and distinction?

Man I was about to ask the same thing, but then I thought why not look for myself...

Last year: 68 D, 49 M.

Very nice grade boundaries in my opinion. However I do think that they'll be higher this year, seeing as overall, the paper was slightly easier than last year's.

Reply 30

spex

By inspection really. It implied f = f^-1 so i looked at values of a that made it true. a=-2 did the trick quite nicely.

Reply 31

Cities

apel

How did you do question 6 part 2. with the ff(x) couldn't do it so couldn't draw graphs

ff(x) = x, hence f(x) = f-1 (x) [self-inverse]

So basically you found the inverse and manipulated it such that a would enable the function to become self inverse.

Reply 32

Cities

Yeh back to my previous question: did anyone elegantly do 7b)?

It took me a good 15 minutes to scrounge 3-4 marks using a method that could be described only as labyrinthine.

Reply 33

sam1990sam

bballer4life

does any1 know what the grade boundaries are for a pass, merit and distinction?

i have no clue it changes every year though i may get around 70%

Reply 34

sijc

Could somebody please show me what the graphs looked like on question 6

Reply 35

rkd

DFranklin

The way we're taught to solve cubics - trial and error of the factor theorem, and you stumble across f(2)=0 pretty quickly.

Reply 36

spex

For 7b you just need to prove the cosines are the same for angle ABL and CBL

Find the cos of each one, then show they're the same. I thought it was trivial which makes me doubt i'm right now lol.

Ok i'm starting to worry because i know i got the right answers, i'm just not sure i showed that the cosines were the same :/

Reply 37

Totally Tom

i think i got 8/9 for q in question 5 part a.

did everyone else get 9/8 ?!?!?

Reply 38

Totally Tom

spex

For 7b you just need to prove the cosines are the same for angle ABL and CBL

Find the cos of each one, then show they're the same. I thought it was trivial which makes me doubt i'm right now lol.

clever

Reply 39

Cities

spex

For 7b you just need to prove the cosines are the same for angle ABL and CBL

Find the cos of each one, then show they're the same. I thought it was trivial which makes me doubt i'm right now lol.

?!?!?!?!?!?!?

What the **** was I thinking!!!

I tried to derive it from first principles.

**** I should have known show thats require less effort that they first suggest.

Related discussions

Latest

Articles for you

Writing a physics personal statement: expert advice from universities

Writing a mathematics personal statement: expert advice from universities

Mathematics with physics degree personal statement example (1g) Cambridge, Manchester offers

Mathematics with philosophy degree personal statement example (1a) IB study - St Andrews, Bristol offers

Mathematics AEA Discussion Thread (Timings Passed)

Related discussions

Latest

Trending

Trending

Articles for you