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STEP Prep Thread 2016 (Mark. II)

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Would you be able to check my reasoning for the first part of q4? I believe my reasoning is correct but slightly different to the ms.
@jjsnyder

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Reply 561

MathHysteria

Original post by EnglishMuon

Would you be able to check my reasoning for the first part of q4? I believe my reasoning is correct but slightly different to the ms.
@jjsnyder

2015 Paper 1 Q4, yes? Seems like a sound argument to me.

Reply 562

IrrationalRoot

Original post by EnglishMuon

Would you be able to check my reasoning for the first part of q4? I believe my reasoning is correct but slightly different to the ms.
@jjsnyder

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I enjoyed that Q :smile:

. Last part was a lot shorter than I expected though.

Reply 563

EnglishMuon

Original post by MathHysteria

2015 Paper 1 Q4, yes? Seems like a sound argument to me.

thanks

Reply 564

Farhan.Hanif93

Original post by EnglishMuon

Would you be able to check my reasoning for the first part of q4? I believe my reasoning is correct but slightly different to the ms.
@jjsnyder

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Original post by MathHysteria

2015 Paper 1 Q4, yes? Seems like a sound argument to me.

Your reasoning is slightly flawed without further justification. What you can claim is that the curve has a parameterisation of the form

x=2\tan t, y= \tan ^2 t

, where

0\leq t < \pi/2

- but this is certainly not unique. In this particular parameterisation, why must this parameter

t

be related to

\theta

as you've defined it?

Reply 565

MathHysteria

Original post by IrrationalRoot

I enjoyed that Q :smile:

. Last part was a lot shorter than I expected though.

I enjoyed all three of last year's papers (besides a couple of awkward questions). Looking forward to trying the 2016 papers soon.

(Of course, I don't have the pressure of doing them under exam conditions, so I get to relax as I do them - lucky me! Mind you, my policy on exams has been guided by a friend of mine from my undergraduate days, who said "How often is it that someone gives you a booklet of interesting questions and promises nobody is going to disturb you for three hours?"...)

Reply 566

MathHysteria

Original post by Farhan.Hanif93

(...) why must this parameter

t

be related to

\theta

as you've defined it?

This is a good point - one which I did not notice. A bit of parametric differentiation should show the result you need.

Reply 567

Farhan.Hanif93

Original post by MathHysteria

A bit of parametric differentiation should show the result you need.

Indeed. Along with the observation that

\theta

defines the gradient of the tangent rod, which I'd argue is unavoidable in any approach to this part of the question.

Reply 568

Number Nine

Original post by Zacken

This is the way I would do it:

that is a bigger mess than my life there is no way in heck you would do it that way

zacin stop lying on internet

Reply 569

EnglishMuon

Original post by Number Nine

that is a bigger mess than my life there is no way in heck you would do it that way

zacin stop lying on internet

lol I seem to remember having that in my workings somewhere :tongue:

Reply 570

EnglishMuon

Original post by Farhan.Hanif93

Your reasoning is slightly flawed without further justification. What you can claim is that the curve has a parameterisation of the form

x=2\tan t, y= \tan ^2 t

, where

0\leq t < \pi/2

- but this is certainly not unique. In this particular parameterisation, why must this parameter

t

be related to

\theta

as you've defined it?

ah yes that makes sense, thanks. I did think that maybe I needed a little more but I hoped I could get away with it due to time pressure but yeah for the sake of a mark or two Ill justify it in future.

Reply 571

Number Nine

Original post by EnglishMuon

lol I seem to remember having that in my workings somewhere :tongue:

dont egg him on to lie more

Reply 572

Insight314

Original post by KingRS

Wasn't complaining, merely providing reasoning. Yeah, ill do that. I suppose there's not much else i can do. It's not that i panic or anything but rather I lose my edge and take longer to do questions which can be a problem under timed conditions.

How come you have found out that you take longer to do questions when you haven't done STEP prep in a while? I am just surprised and curious, don't you think it might be just psychological? Does anyone else experience this?

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