STEP III 2012 Discussion Thread
Maths exam discussion - share revision tips in preparation for GCSE, A Level and other maths exams and discuss how they went afterwards.
-
Re: STEP III 2012 Discussion ThreadI agree, but the thing is that without this info we couldnt do the question! I ended up saying let z = x^2/4 (without any explanation) in order to show the result given in Q1(Original post by maksokio)
I think there was a sentence omitted from question one, one that should read "where z=y^n*(something)" like in 2010 STEP II that they forgot to type another sentence about the Useless Eustace question about the range of value of the angles (0<θ<2π).
It may be possible that someone can work out the value of z (as a function of y) by directly integrating the right hand side of the the formula given. -
Re: STEP III 2012 Discussion ThreadI think Farhan told me that it was a nice paper if you liked summing(Original post by TheMagicMan)
Not in my book. I've consulted about 25 offer holders and about 70% thought it was on the hard side
This was posted from The Student Room's iPhone/iPad App -
Re: STEP III 2012 Discussion Thread
I guess im alone when i say i did number 1 completely (Yes n=1 and n=-2)... But that's it. I did most of 6 and 7 (15+) and then 3 (not even) partial solutions (2,4,5), possibly about 5 marks each.
By the way this is me being hopeful
I personally thought it was harder than previous years, but im generally not a good judge of what an easy and hard paper isLast edited by desijut; 28-06-2012 at 16:44. -
This was my opinion. I thought there was a sentence missing as they usually aren't so blunt at setting up the question(Original post by maksokio)
I think there was a sentence omitted from question one, one that should read "where z=y^n*(something)" like in 2010 STEP II that they forgot to type another sentence about the Useless Eustace question about the range of value of the angles (0<θ<2π).
It may be possible that someone can work out the value of z (as a function of y) by directly integrating the right hand side of the the formula given.
This was posted from The Student Room's iPhone/iPad App -
Re: STEP III 2012 Discussion ThreadI am afraid that can not be mate, since that wouldnt give (dy/dx)^3 that is contained in the right hand side.(Original post by B Jack)
I didn't do question 1, but I noticed z=(y^n)(dy/dx)^2
apologies for that, total nonsenseLast edited by maksokio; 28-06-2012 at 18:05. -
Re: STEP III 2012 Discussion ThreadIt's factored out, the dy/dx is(Original post by maksokio)
I am afraid that can not be mate, since that wouldnt give (dy/dx)^3 that is contained in the right hand side.
-
Re: STEP III 2012 Discussion ThreadYou forget there was a dy/dx outside the brackets(Original post by maksokio)
I am afraid that can not be mate, since that wouldnt give (dy/dx)^3 that is contained in the right hand side. -
I sent an email to the teacher at my school who's a step problem writer... We'll see what he says... I would be shocked if it actually was a mistake(Original post by RacingPro97)
I agree about Q1 - I was worrying this morning thinking that I might be the only person with a printing error or something!
This was posted from The Student Room's iPhone/iPad App -
Re: STEP III 2012 Discussion Thread
Hmmm...I did 8 fully; everything but ii) on 2; everything but the a^3 bit on three; the first two proofs for four; and everything but the inequality on 7. Oh...and I solved first bit of 1 and got z = f(y) (lulwut?)...didn't go well for me. How would you rate my chances of getting a 1 ?_?...(anyone feel free to answer).
-
Re: STEP III 2012 Discussion ThreadYeah, I worked that much out for Q1 that n was -2 or -1/2 cannot remember now, and first part was n =1(Original post by desijut)
I guess im alone when i say i did number 1 completely (Yes n=1 and n=-2)... But that's it. I did most of 6 and 7 (15+) and then 3 (not even) partial solutions (2,4,5), possibly about 5 marks each.
By the way this is me being hopeful
I personally thought it was harder than previous years, but im generally not a good judge of what an easy and hard paper is -
Re: STEP III 2012 Discussion Threadall u had to say was the n was 1. then sub in the formula for root(y). then solve a simple differential eqn. for the next part, n was 3 or 4. the formula for dz/dx was just a product of two differentials.(Original post by TheMagicMan)
I sent an email to the teacher at my school who's a step problem writer... We'll see what he says... I would be shocked if it actually was a mistake
This was posted from The Student Room's iPhone/iPad App -
Re: STEP III 2012 Discussion Threadthe question did not have a cubed dy/dx(Original post by maksokio)
It may be that I am being stupid here for some reason
but I think that if z=y^n(dy/dx)^2 then dz/dx=ny^(n-1)(dy/dx)^2+2y^n(dy/dx)(d^2y/dx^2) when the formula reads dz/dx=ny^(n-1)(dy/dx)^3+2y^n(dy/dx)(d^2y/dx^2)
it was squared
-
Re: STEP III 2012 Discussion ThreadI thought that took the piss tbh, I wanted to do something different instead of the same tedious thing again.(Original post by fruktas)
I thought question 2, was sort of a 'typical' STEP question. They guided you through something, and asked you to repeat it all yourself for a different function

but I think that if z=y^n(dy/dx)^2 then dz/dx=ny^(n-1)(dy/dx)^2+2y^n(dy/dx)(d^2y/dx^2) when the formula reads dz/dx=ny^(n-1)(dy/dx)^3+2y^n(dy/dx)(d^2y/dx^2)