STEP Prep Thread 2017

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Doing part (ii) again is unnecessary; you definitely don't want to waste time making unnecessary justifications in STEP - it should all be as concise as possible.

The 'looking at signs method' can easily be shown to work with all such cubes of binomials, you can quickly prove this is you like since it's very easy.

It seems that you think this isn't rigorous enough, but it really does just follow from the fact the magnitude of each term in the binomial expansion will clearly be the same as before, but the signs are switched every other term due to the powers of -1 (and the rational and irrational terms alternate).

ofc what you said makes perfect sense.

Thanks I see what you mean :smile:

Reply 221

username1162972

Original post by IrrationalRoot

It's pretty intuitive that it works for the positive solution as well. It's very easy to quickly verify this in your head; just think about how the signs work out when you cube the binomial.

Indeed, exactly how I thought about it back when i did it.

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Reply 222

girlwonder17

For page 3 in the expansions of the u^11 example:

The very last stage when you do ((u^2)^2)^2 * (u^2 * u)

I have (3782321 + 3621520sqrt5) * (207 + 94sqrt5) = 782940447 + 749654640sqrt5 + 355538174sqrt5 + 1702114400= 2485054847+1105192814sqrt5

But when I do this on my calculator I have:

4054080964

But when expanding you get a (Sqrt5 part)...

SO how is it an integer answer on calculator!

Reply 223

ARASH123g

hi
I

Attachment not found

dont get this last bit of the question
could someone please explain it
thanks

Screen Shot 2016-09-24 at 00.26.26.png197.6KB

Reply 224

Zacken

Original post by ARASH123g

hi
I

Attachment not found

dont get this last bit of the question
could someone please explain it
thanks

find gradients of PQ and RS, set them equal, solve.

Reply 225

username1162972

Original post by girlwonder17

Sorry but wth ar eyou talking about?

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Reply 226

girlwonder17

Original post by physicsmaths

Sorry but wth ar eyou talking about?

Posted from TSR Mobile

the link never posted mb

It is from the sttep 1 2004 answer q1

http://files.physicsandmathstutor.com/download/Maths/STEP/Solutions-and-Reports/2004%20Hints%20and%20Answers.pdf

Page 3, last line of question 1

Reply 227

Krollo

Hi guys,*

I've been on-and-off working on some notes for step mechanics, on the basis that it's often a little underrepresented hereabouts. It's by no means finished, and probably full of errors, but I'll put it up now so you can suggest changes and hopefully benefit from it.

K

https://docs.google.com/document/d/1OiG2tmZ1OENPK9U2ob8HUDyzbBzsdRvFdCANbH4a17Y/edit?usp=sharing*

Reply 228

FriendlyPenguin

That reminds me, guys, always give the statistics section of STEP a chance too. Often, you don't need to know much about statistics in order to answer one of the questions. Just glance at it, at the very least.

I personally think its a very good investment to learn some statistics, even if it is solely for STEP, and even if you are sure that you are going to ace the pure and applied sections.

(edited 7 years ago)

Reply 229

Injective

Original post by Mathemagicien

This is actually very true.

Reply 230

DFranklin

Original post by Krollo

One thing that seems to be missing is using the energy approach to find the period of small oscillations about an equilibrium point. This seems to be coming up quite a lot in STEP III in recent years (although I looked at the specification and couldn't actually see it on there :confused:

)

Reply 231

Luke7456

Original post by Mathemagicien

I just keep hearing contradictory things from some sources I am told focus on mechanics and statistics only since the pure stuff is near impossible then other sources say focus on the pure stuff as the mechanics and statistics is near impossible.

then on other sources apparently statistics questions are easy godsends.

Just hear contradictory stuff all over the place. I am thinking best strategy is try be prepared for everything. I dont know.

Reply 232

DylanJ42

Original post by Luke7456

The best strategy is to do what you're must comfortable doing. I'd say try all, if not almost all, of the questions in your first few papers and see what you like and don't like. Then go from there.

Also every question is a godsend if you know how to do it, just because someone else is amazing at stats and can get 40/40 in the 2 stats questions doesnt mean everyone can.

(edited 7 years ago)

Reply 233

FriendlyPenguin

Original post by Luke7456

I just keep hearing contradictory things from some sources I am told focus on mechanics and statistics only since the pure stuff is near impossible

That is the worst advice I have ever heard for STEP.

Reply 234

Luke7456

Original post by Mathemagicien

That is the worst advice I have ever heard for STEP.

Well one thing I have noticed about exams where you have options on which questions you can answer eg answer 4 of 6 or in steps case 6 of 13 is that you can often pick several topics learn them really well then miss out everything else. Which works great when you get the right questions on your topics. However totally goes sour when you either dont get your questions or do but get asked it in a totally alien way and cannot figure it out.

I have not even started looking at steps yet plan to start end of dec provided the thing i am worrying about is just worrying about nothing. (personal stuff long story)
So I would trust your advice. I do have a reasonable back ground with statistics and have a brother who did a degree in psychics but dropped out and a cousin that did a PHD from cambridge in psychics so might be able to get help with mechanics.

I think for these reasons i can focus on statistics and mechanics but I wouldn't like to leave myself not been ready for the pure stuff.

I think the best strat is to try and learn everything that way I am in a very strong position as if the papers throw me curve balls I have a lot of other stuff to fall back on.

assuming everything goes according to plan (still a lot of if buts and maybes) I should have more then full time working hours to literally focus on nothing else but steps from 2nd jan onwards. of course id be starting it from then so meh.

btw anyone up for sharing tutors? eg pay a step tutor between us to teach us some? might work out cheaper and get value for money. I can talk about that nearer jan i guess.

Reply 235

DFranklin

Original post by Luke7456

If you've got the time/ability, being prepared for everything is certainly going to maximize your chances. That said, some pragmatism:

Because there are 8 pure questions and only 5 applied, plus that It's hard to do well on the applied questions without being pretty good at the pure side of things (you'll often need strong algebra, trig and calculus skills), you really can't plan on doing STEP without being reasonably strong on the pure side. This leads many people to concentrate their efforts on the pure topics.

On the other hand, one key factor in doing well in STEP is choosing the right questions - or to put it another way, avoiding the "wrong" ones. If you just focus on pure, you only get to avoid 2 questions before it starts affecting your grade. If you can also attempt just one applied question, all of a sudden you get 3 questions you can avoid instead of 2, which is quite a big difference.

This is particularly relevant because if you look at actual STEP questions, the range of common topics on the applied side is actually a fair bit narrower than the full syllabus. So if you're not trying to do *everything*, but just give yourself some extra options, it really needn't be that much work. (Last time I looked, you could skip almost the entire S4/S5 syllabus and on average it would lose you less than 1 question total over all 3 papers, for example).

One particular caveat about many of the stats questions: yes, they are often relatively quick/short/easy, but at the same time, they are generally the questions where it's easiest to *completely* mess up (due to making a bad assumption, like thinking variables are independent when they aren't, etc). If you do a pure question and think you got 20/20, it's very unlikely you drop more than a couple of marks. With stats it happens a lot more frequently.

Reply 236

sweeneyrod

Original post by Luke7456

I think for these reasons i can focus on statistics and mechanics but I wouldn't like to leave myself not been ready for the pure stuff.

I think the best strat is to try and learn everything that way I am in a very strong position as if the papers throw me curve balls I have a lot of other stuff to fall back on.

I think focusing on the pure is the best strategy, since it accounts for most of the questions and has less variance than the applied. It is definitely worth learning a little of both mechanics and stats, so you can take advantage of the occasional gift question (thank you 2016 STEP III Q 12!) and worth learning more of either (or both) if you are interested in them. But it isn't uncommon for the applied to have a couple of really difficult questions, so having a plan to e.g. do 4 applied questions and a pure is probably not a great idea.

Reply 237

Luke7456

well things went according to plan, now I have a free run at doing nothing else but maths for 3 months straight and then if i can all the maths modules i plan to sit this year by 2nd jan ( I think I can) I have 5 months straight for steps 1 and 2. should all be good now. Yeah i think i will follow others advice and focus mostly on pure whilst making sure I am familiar with stats and mechanics but will see later when i get there.