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The 2012 STEP Results Discussion Thread

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Original post by gff
The best advice I can give is to keep doing questions. If you can manage a question per day, then that will be certainly very good.
Considering the numbers, from I, II and III papers 2011-2004 you have roughly 150-160 pure questions only. So, it can keep you busy for about 5-6 months.
Also, in my opinion, doing a whole paper in a day and then no questions for two weeks is a bad strategy.


I agree with you on one question a day being a very good amount and one to aim for, so I've added it to the front post to give lurkers an idea.

Anyone with more experience, please yell if that seems badly off. :smile:
Original post by DontBeJelBeReem
Mwhaha, that was a really bad way to put it i guess! But it's not very neat, i was hoping i could carry n from the earlier part of the question, im sure of a link but cannot see it :frown:


Actually I agree. There must be a more pronounced link.
Original post by DontBeJelBeReem
STEP i 2002. ]

Heres the solution http://www.thestudentroom.co.uk/showpost.php?p=18451574&postcount=31
I cant do the very last bit where you need to find the roots of a quartic. The solution uses guess work to find the roots, and then factorises, but surely theres a more 'mathematical' way that relates to the question? Maybe im just being pedantic..

I think spotting the first root by inspection helps a lot. Then you can form three equations relating the roots with the coefficients of the remaining cubic. For the equation with the minuses in it, try factorising the number on the RHS. What do you notice?
Is it okay to adopt pi notation? I isn't on the a-level spec....
Original post by Farhan.Hanif93
I agree mostly. Just felt I had to mention it as the OP hadn't got the k=4 case comfortably despite (I assume) trying it so generalising might not have been the best option in that situation.


Having actually worked the question through in full, I think we may have a contender for the step question with the shortest solution
Original post by wcp100
Is it okay to adopt pi notation? I isn't on the a-level spec....


You can use any accepted notation...or you could just define it in the exam: 'i=1nai\prod^n_{i=1} a_i is the product of the first n terms of the sequence aia_i' or something like that
Original post by TheMagicMan
Having actually worked the question through in full, I think we may have a contender for the step question with the shortest solution

Possibly! Seems like any difficulty in the question is based around spotting the pattern. If you can do that with minimal working, the question is short. :p:

The shortest STEP question I've ever done is STEP I 1987 Q4.
Original post by TheMagicMan
You can use any accepted notation...or you could just define it in the exam: 'i=1nai\prod^n_{i=1} a_i is the product of the first n terms of the sequence aia_i' or something like that


Fair enough. Thanks...
Original post by Farhan.Hanif93
Possibly! Seems like any difficulty in the question is based around spotting the pattern. If you can do that with minimal working, the question is short. :p:

The shortest STEP question I've ever done is STEP I 1987 Q4.


How many lines was that?
Original post by wcp100
Fair enough. Thanks...


Although if they won't accept it you could always use for ai>0a_i>0

aiexp(lnai)\displaystyle\prod a_i \equiv \exp({\sum ln a_i}) :tongue:
Original post by TheMagicMan
Although if they won't accept it you could always use for ai>0a_i>0

aiexp(lnai)\displaystyle\prod a_i \equiv \exp({\sum ln a_i}) :tongue:


I know it's simple, but that looks cool:colone:
Original post by Farhan.Hanif93
I think spotting the first root by inspection helps a lot. Then you can form three equations relating the roots with the coefficients of the remaining cubic. For the equation with the minuses in it, try factorising the number on the RHS. What do you notice?


Thanks for the tip, will try it tomorrow and see if i notice :cool:
Original post by TheMagicMan
How many lines was that?

3 at best. I could've probably squeezed it onto a line. :p:

Spoiler

Does 0 count as a positive integer?
Original post by Physics Enemy
Does 0 count as a positive integer?


Nope, zero is only included when it says non negative.
Original post by Aristotle's' Disciple
Nope, zero is only included when it says non negative.

Wow, I always thought it counted, or at least thought it was a 'grey area' and you could include it. :s-smilie:
Original post by Physics Enemy
Wow, I always thought it counted, or at least thought it was a 'grey area' and you could include it. :s-smilie:


the definition of +ve means it can't be.
Original post by ben-smith
the definition of +ve means it can't be.

I obviously didn't know the definition. :tongue: I thought you could include zero too, ohh well.
Original post by Physics Enemy
Wow, I always thought it counted, or at least thought it was a 'grey area' and you could include it. :s-smilie:


The natural numbers can include 0 (although I would not use this definition) but the positive integers cannot. There are also of course the whole numbers which is another grey area
Original post by TheMagicMan
The natural numbers can include 0 (although I would not use this definition) but the positive integers cannot. There are also of course the whole numbers which is another grey area

Yes, that's the grey area I was referring to. In my mind I had equated natural numbers with positive integers, as people often interchange the two names, so I lumped zero in with both. But thanks. :smile:

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