The 2012 STEP Results Discussion Thread

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what ratio result? I'm not saying it's complicated, just that the way I did it took quite a lot of algebra. It' plausible that I just don't know some vector results and have used more elementary tools.

I'm pretty sure all methods should be acceptable.

I've found what the position vectors of the orthocentre and circumcentre are, and proved by the definitions that they're indeed those.
Then, I said that if the centroid is in the line segment joining the orthocentre and circumcentre, then it must lie on that vector line.

Spoiler

Original post by Rahul.S

...

I tend to use only standard things that are "obvious", or appear in the formulae book, as the above one does. :biggrin:

Reply 1201

Dog4444

Original post by Rahul.S

I think ive seen the name of few results in mark schemes and examiner reports.....if I remember right Ceva's theorem is one :tongue:

quoting it is enough? wouldn't a quick proof be required?

It's definitely out of syllabus, so not supposed to be there. Is it used in official solution?

Reply 1202

Rahul.S

Original post by gff

I tend to use only standard things that are "obvious", or appear in the formulae book, as the above one does. :biggrin:

fair enough. :colone:

Reply 1203

TheMagicMan

Original post by Rahul.S

I think ive seen the name of few results in mark schemes and examiner reports.....if I remember right Ceva's theorem is one :tongue:

quoting it is enough? wouldn't a quick proof be required?

I would think that if you can quote the name of a theorem, than you can use it...that is at least the standard they apply in olympiads

Reply 1204

Rahul.S

Original post by Dog4444

It's definitely out of syllabus, so not supposed to be there. Is it used in official solution?

well yh the name of the theorem was given for a vector STEP II question I did.....I think it was in the examiner report.

Reply 1205

Rahul.S

Original post by TheMagicMan

I would think that if you can quote the name of a theorem, than you can use it...that is at least the standard they apply in olympiads

yh I think we can....especially if its in the formula book and they don't ask to prove it. I wouldn't know about olympiads :tongue:

Reply 1206

shamika

Original post by TheMagicMan

I would think that if you can quote the name of a theorem, than you can use it...that is at least the standard they apply in olympiads

The difference is that the Olympiad (at least at the international stage) goes to great lengths to check the literature to ensure you can't just quote a result and solve the problem trivially.

There's quite a few STEP problems that you can 'brutalise', that is, you can quote the right result and get the result out straight away. STEP problems are hard because they force you to use the limited A-Level toolbox to solve interesting problems.

I just wouldn't quote a result without proof and expect to get full marks, unless I also proved said result and the question clearly doesn't care which way you solve the problem.

Reply 1207

Dog4444

Original post by hassi94

Right I need some help on STEP 2 2002 Q5. Ive gotten k = 1/(1-a) from part ii and gotten to a = abk(1-ab) in part 3. Can't see how to get to the cubic though.

Thanks a lot guys.

What did you do in the first part?
I tried to find general formula and got:

x_n=k^n(1-x_0)(1-x_1)...(1-x_{n-1})x_0

But don't know what to do next.

Reply 1208

Intriguing Alias

Original post by Dog4444

What did you do in the first part?
I tried to find general formula and got:

x_n=k^n(1-x_0)(1-x_1)...(1-x_{n-1})x_0

But don't know what to do next.

I did a sort of loose induction. I can't remember my exact workings right now so I'll show you a bit later if still needed. Basically showed that X1 is between 0 and 1 for the ranges of k and X0 (rather than necessarily 'proved') then as it's inductive it's true for all n, which I felt satisfies the 'proof' element..

I did it basically exactly as dadeyemi did here:

http://www.thestudentroom.co.uk/attachment.php?attachmentid=67568&d=1238765634

(edited 12 years ago)

Reply 1209

Physics Enemy

Original post by shamika

Sorry that's just not true - I got 11 A* GCSE/ 5 A's at A-Level with 90 UMS+ in each. My trick was knowing how predictable the exams were going to be. It doesn't require effort.

I'm not saying anyone should follow my example (in fact, I actively discourage it as I was a smug little so-and-so in sixth form) but it genuinely is possible to do that well without effort.

Imperial on the other hand required a ton of work and crazy hours towards the exams to make up for my lack of genuine understanding in the first year. But then after that Imperial exams (at least the maths ones) are sometime predictable too so you can coast those subjects.

Its not intelligence (at least, not on my side at least). Its just good exam technique :smile:

(note this doesn't work for STEP because you actually need to have a brain and work at it, something I was very against when I was 17...)

Other than being a liar, the only explanation I can give for your statement is that you went to a good private/grammar school and so the 'effort' was largely done for you by excellent teaching, parenting, private tutors, etc. Even in that scenario, there's still heaps of coursework and exam prep to do.

When someone says 'I did very little', my view of that is meaning something like 'I may as well have never gone to school and walked into the exams cold'. So it makes me roll my eyes.

Another thing; Imperial grads are notorious for being nerds/bookworms/socially awkward, so the whole 'I don't try' or the talented slacker MYTH, is that.

At A-Level at least, I do agree it's about exam technique. How did you get good exam technique though? Out of the sky? Deary me ...

(edited 12 years ago)

Reply 1210

shamika

Original post by Physics Enemy

It's alright. My current set of exams have made me realise just how crap I really am :smile:

Reply 1211

Physics Enemy

Original post by shamika

I did go to a grammar school for A-Levels, but went to a normal comp for GCSE's.

Not requiring effort isn't the same as not working. For GCSE's, I did turn up to class, and wasn't disruptive or anything. I just found that it came easily to me, that's all.

Yes, but that still leaves a heap of coursework to do. Who did that? :s-smilie:

Original post by shamika

I worked very hard at Imperial. I don't get why this is hard for you to believe. I'm not pretending I'm a genius (I've said on these boards before that my grades give a false impression of my intelligence). I had Physics friends who were in a similar boat (never had to work before uni). I've got friends at work who went to Oxbridge/Warwick/LSE/UCL who say the same thing. Maybe our definitions of effort differ but I know for sure that I'm not the only one like that.

Oh, and not every course at Imperial was hard. There were plenty of courses which were quite easy (Algebraic Number Theory, I'm looking at you!) where pretty much everyone walked out after an hour into the exam since we'd all finished.

I believe you worked at ICL, due to the amount of material to cover. I'm also aware not all ICL courses are hard. I think there's a lot of nonsense spouted though; ICL is full of nerds.

Original post by shamika

Spotting patterns isn't genius, not when they're as obvious as knowing what sorts of responses are required in an A-Level/GCSE paper to score all the buzzwords, and hence the marks.

Trying to do the same on my current exams is an entirely different story... :frown:

Yes, it's exam technique, we know that. This was about effort, remember! Exam technique requires effort, that's all. It takes a lot of effort to learn the markschemes and develop that style/rigidity to get all the marks. It's a game. Why pretend otherwise though? :s-smilie:

Reply 1212

Aristotle's' Disciple

Original post by Physics Enemy

...

You seem to care WAY too much. Besides why is it so hard for you to believe? There's a guy at my sixth form who works in class only and hardly ever drops marks. No shame if you're one of the ones who has to grind to get the results. What's important is you do get the results, and the effort you put in is sufficient. If you can get the grades with minimal work, good for you.

Reply 1213

Physics Enemy

Original post by Aristotle's' Disciple

There's a guy at my sixth form who works in class only and hardly ever drops marks.

How do you know that? :s-smilie:

Hard workers in class tend to be hard workers at home. Slackers in class tend to slack at home. I care as it's a lie and potentially detrimental, that's why. Propagating lies is bad.

Reply 1214

Aristotle's' Disciple

Original post by Physics Enemy

How do you know that? :s-smilie:

Hard workers in class tend to be hard workers at home. Slackers in class tend to slack at home. I care as it's a lie and potentially detrimental, that's why. Propagating lies is bad.

He does ALOT of extra curricular, and you can generally tell from class too, said person can do questions our teachers struggle with etc. and always finishes in minimal time (they have an offer from Fitzwilliam for a non math course). Also, I slack in class but work pretty hard at home, so that theory goes out the window. It's only detrimental to you because of your mindset, just understand some people have to work harder than others to get places, and there's no shame in that. Propagating lies is bad, but these aren't lies, you're just choosing not to believe them. Anyways, this thread is for STEP QUESTIONS, so if you wanna carry this conversation on, inbox me.

Reply 1215

Physics Enemy

Original post by Aristotle's' Disciple

Propagating lies is bad, but these aren't lies, you're just choosing not to believe them.

I don't believe 12 subjects worth of GCSE knowledge gets learnt with barely any effort. I also don't believe heaps of coursework, for many subjects, gets done without putting in the time.

I'm also very wary of people who 'claim' they do little work, despite clear signs to the contrary. Yes, I can believe some people have a bit of a flair for certain things and that's cool; not the 'I did no work and got XYZ' nonsense.