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# Current Year 12 Thread Mark VI Tweet

Discussion for A-Level students and for those choosing their A-Level subjects.

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1. Re: Current Year 12 Thread Mark VI
(Original post by silentlife)
It's a variant of this "proof":

"For all those serious Maths buffs... lemmas and theorems!
1. Lemma: All horses are of the same colour.
Proof (by induction):
Case n=1: In a set with only one horse, it is obvious that all horses in that set are the same colour.
Case n=k: Suppose you have a set of k+1 horses. Pull one of these horses out of the set, so that you have k horses. Suppose that all of these horses are the same colour. Now put back the horse that you took out, and pull out a different one. Suppose that all of the k horses now in the set are the same colour. Then the set of k+1 horses are all the same colour. We have k true => k+1 true; therefore all horses are of the same color.

source: http://www.jokebuddha.com/Lemma#ixzz1xnh7HTlq"
All you have proved there is that in the situation where all the horses are the same colour, all the horses are the same colour. If I could make those kinds of assumptions without having to give an explanation I could literally prove anything.
2. Re: Current Year 12 Thread Mark VI
(Original post by Llewellyn)
Ditto on messing up C4

Just keep in mind that the majority of the marks are for method and workings. The actual answers aren't worth that many marks.
I know, but the error in the differential equations question was right at the beginning, so all working after that point is also wrong

I'd guess I've lost about 4 marks elsewhere + whatever I lost on the differential equations question (could be as much as 6 or 7 lost due to the question which relied on the equation I made). 10 or 11 marks lost doesn't nescessarily rule me out of an A*, (heck, in june 2011, 65/75 would've got 100 UMS!) but I don't think it was that hard a paper in general, so its unlikely that I'll get away with it.
3. Re: Current Year 12 Thread Mark VI
(Original post by Llewellyn)
All you have proved there is that in the situation where all the horses are the same colour, all the horses are the same colour. If I could make those kinds of assumptions without having to give an explanation I could literally prove anything.
The "proof" I saw was stronger, but I can't find it on the internet.

(of course there's going to be holes...)
4. Re: Current Year 12 Thread Mark VI
(Original post by silentlife)
The "proof" I saw was stronger, but I can't find it on the internet.

(of course there's going to be holes...)
I know, I know

My biggest gripe is proof by contradiction. It's really stupid in my opinion. You assume that whatever you're investigating will only have 2 outcomes. And by disproving "not this" you prove "This". It's actually stupid.

e.g. I have no hat. Lets say we try to prove my hat is red. Assume the hat is not red: clearly this is not true. Therefore, my hat is red. But in fact I have no hat.

And now that I've finished C4 I'm completely free to let rip that proof by contradiction is one of the most silly and perilous lines of logic that you can apply in almost any situation.
5. Re: Current Year 12 Thread Mark VI
(Original post by Llewellyn)
I know, I know

My biggest gripe is proof by contradiction. It's really stupid in my opinion. You assume that whatever you're investigating will only have 2 outcomes. And by disproving "not this" you prove "This". It's actually stupid.

e.g. I have no hat. Lets say we try to prove my hat is red. Assume the hat is not red: clearly this is not true. Therefore, my hat is red. But in fact I have no hat.

And now that I've finished C4 I'm completely free to let rip that proof by contradiction is one of the most silly and perilous lines of logic that you can apply in almost any situation.

Maths
6. Re: Current Year 12 Thread Mark VI
(Original post by chickenonsteroids)

Maths
http://en.wikipedia.org/wiki/G%C3%B6...eness_theorems

If you disagree with proof by contradiction a quarter of all "proofs" would not work...
7. Re: Current Year 12 Thread Mark VI
The logic in proof by contradiction is flawed because it immediately assumes that only 2 outcomes are possible. It is not inapplicable, I just don't like it.
8. Re: Current Year 12 Thread Mark VI
(Original post by Llewellyn)
The logic in proof by contradiction is flawed because it immediately assumes that only 2 outcomes are possible. It is not inapplicable, I just don't like it.
It assumes you know when to apply it.
9. Re: Current Year 12 Thread Mark VI
(Original post by Llewellyn)
The logic in proof by contradiction is flawed because it immediately assumes that only 2 outcomes are possible. It is not inapplicable, I just don't like it.
10. Re: Current Year 12 Thread Mark VI
(Original post by wcp100)
It assumes you know when to apply it.
Yes but the general problem with that is if you know when to apply it, you probably already know the outcome.

I think applying it outside of number theory (and where all numbers are given to be real and positive) is best avoided. It's an accepted technique but generally a proof through inspection or induction or even assuming you are correct and then showing you are is better (in my opinion).
11. Re: Current Year 12 Thread Mark VI
Ok so i'm a regular gig go-er, however the low key bands that i've been supporting for a while are coming to Manchester to play live, and none of my friends listen to them/want to spend money on an artist they don't know.

Is it sad to go to a gig on my own?
12. Re: Current Year 12 Thread Mark VI
Oh god, I'm looking at 95 UMS in C3 if Arsey's grade boundary predictions are right and if I don't lose more marks than it looks like I should for accuracy in some parts...
I hope he's wrong and that 100 UMS goes down to 74/75 or something - now I'm really, really scared about getting an A* overall!
13. Re: Current Year 12 Thread Mark VI
Anybody watched the football?
14. Re: Current Year 12 Thread Mark VI
(Original post by silentlife)
Anybody watched the football?
yuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu uuuuuuuuuuuuuup
15. Re: Current Year 12 Thread Mark VI
(Original post by Llewellyn)
Yeah I really want that A* to take pressure off for next summer. The Unis I'm looking at normally include an A* so hopefully I've covered that possibility. C3 also went "well" which makes my chances look quite good (fingers crossed for no weird grade boundaries).

Yep it's practice/ mocks. I normally allocate 2 hours 30 per paper because at that point I've normally solved enough questions. There is some repetitiveness in STEP so it's quite helpful, especially as I have quite a good short-term memory.
Yh it'd be such a wounder if you had to put down A on the UCAS application!

Ahaha that's good then. I just haven't been able to get my head around STEP yet. It's been ages and I'm still just like 'what? :/' whenever I do a question. Good luck on your exam.
16. Re: Current Year 12 Thread Mark VI
anyone up?!
17. Re: Current Year 12 Thread Mark VI
me
18. Re: Current Year 12 Thread Mark VI
me too
19. Re: Current Year 12 Thread Mark VI
me three
20. Re: Current Year 12 Thread Mark VI
me four