STEP Prep Thread 2017

is there any data anywhere showing the correlation between an SS and a first, 11 and 2:1/2:2 etc? pretty sure i saw somewhere STEP performance is by far the best indicator of tripos success

Here you go. I think it makes sense, but I'm no Siklos. Comments/criticism welcome:

In this question, $f(x)=x^x$

1) Solve $f(x)=1$ for $x>0$
...

Zacken, do you have any idea of what my mark break down will be? I've written a description in a previous comment.

No takers? All STEPped out? Too challenging? Too trivial?

I'll put up a solution tomorrow evening if no one attempts it by then.

I think the fact that people focus too much on pure is biting them in the ass. Both the stats questions are very very easy and there's one easy pure (Q4) and another moderate pure (Q6), granted the rest don't look great, so I can certainly see boundaries being lower than usual.

Learn stats, people!

What's scary is that only half of us will get in... I have a feeling I know which I'll be in...

Can someone please estimate my mark again?
1) full
3) did most of it but did the last part in a very weird way, and only really found 1 pair or roots with a small arithmetic error
4) mostly complete, in iv didn't manage to write the DE, in f,g, but did everything before
5) full
6) mostly complete, couldn't do T(root2-1) but did T(root3)
8) half, did the stem and i

Can someone please estimate my grade on STEP III?

Q1: Full
Q2: Did (i), calculated the image of a general z under RS and SR (mentioned the trivial solution a=b for part (iii))
Q3: Did (i) and (ii), but got wrong answer with correct method in (ii).
Q4: Full except part (iv)
Q5: Obtained the first two results.
Q6: Full except the T(sqrt2-1) part in (iii).

Hi, would you be able to predict my mark?

Q1 I got all of Question one, except for the fact that I said 10-5/4 was 35/40 as opposed to 35/4, leading to an arithmetic error. However, my method for showing the required inequalities was correct.
Q3 I wrote down the two equations in their factor form, expanded and compared coefficients and got a value for A in terms of alpha,beta,gamma, and delta. (Didn't do much here. Possibly 2/3 marks?
Q5 I did all of the polar coordinates section, however when I found f(theta), I got r=A/(sec^(theta) + sec(theta)tan(theta)) which is an alternative way of writing down the solution, but when it came to plugging in the boundaries, the denominator got a bit awkward. My sketch for 1+sintheta and 4 +4sintheta were perfect and my sketch for f(theta) showed the graph intersecting the two other graphs perpendicularly. So maybe 2/3 marks dropped?
Q6) I used the correct substitution and found the required result for part (i). I then verified the derivative and showed that it followed from that that 1(/1+v^2)dv = 1/(1+u^2)du and made very little progress after that
Q7) I showed the very first part. I then found dy/dx in terms of t but couldn't show that an equation in t would equal zero. However, from there I deduced the equation relating to the determinant and successfully wrote down the geometric interpretation being two tangents intersecting at one point. I then successfully sketched the cases where X^2=a^2 (one graph showing X=a and the other showing X=-a). I then managed to successfully arrive at the values of pq, which you had to show, and then p+q. After this I moved on
Q8) I showed the summation series in the stem of the question, however might drop 1 mark as I wasn't very clear towards the end. I showed the first part completely correctly, but didn't go on to do the second.

That's all I answered. What do you reckon my mark breakdown will be, and do I stand a reasonable chance of getting a 1 in this paper?

Thanks

Hi,

Could someone please estimate my score on STEP II and STEP III?

STEP II:

1) Complete
2) Complete, possibly with minor errors (I am not sure I explicitly stated that a+b is nonzero in part ii) but I analyzed that as well).
5) Complete
6) I did the induction and the inequality in part ii, but did not find the correct C - but I stated without proof that it is 3/2.
7) I did ii) and iii) and proved that f(x)>x in part i. That's all.
8) I stated the equation of the line, but did not obtain the correct p. Without that I was still able to prove that CP is perpendicular to AB (so it didn't follow from the previous part, would I still get marks for that?)

STEP III:
1) Complete
3) Complete
4) Did parts i), ii) and iii) correctly, and also completed iv), but not very rigorously (how much are the first three parts worth?)
7) I didn't get to the equation in part i), but assumed it and completed i). Then I completed ii), but somewhere in the computation I made a slight arithmetic error, maybe the examiners wont even notice.
8) Result and part i)

Thank you for anyone who would tell me which grade I should expect.

Can someone please estimate my mark again?
1) full
3) did most of it but did the last part in a very weird way, and only really found 1 pair or roots with a small arithmetic error
4) mostly complete, in iv didn't manage to write the DE, in f,g, but did everything before
5) full
6) mostly complete, couldn't do T(root2-1) but did T(root3)
8) half, did the stem and i

Can someone please estimate my grade on STEP III?

Q1: Full
Q2: Did (i), calculated the image of a general z under RS and SR (mentioned the trivial solution a=b for part (iii))
Q3: Did (i) and (ii), but got wrong answer with correct method in (ii).
Q4: Full except part (iv)
Q5: Obtained the first two results.
Q6: Full except the T(sqrt2-1) part in (iii).

Hi, would you be able to predict my mark?

Q1 I got all of Question one, except for the fact that I said 10-5/4 was 35/40 as opposed to 35/4, leading to an arithmetic error. However, my method for showing the required inequalities was correct.
Q3 I wrote down the two equations in their factor form, expanded and compared coefficients and got a value for A in terms of alpha,beta,gamma, and delta. (Didn't do much here. Possibly 2/3 marks?
Q5 I did all of the polar coordinates section, however when I found f(theta), I got r=A/(sec^(theta) + sec(theta)tan(theta)) which is an alternative way of writing down the solution, but when it came to plugging in the boundaries, the denominator got a bit awkward. My sketch for 1+sintheta and 4 +4sintheta were perfect and my sketch for f(theta) showed the graph intersecting the two other graphs perpendicularly. So maybe 2/3 marks dropped?
Q6) I used the correct substitution and found the required result for part (i). I then verified the derivative and showed that it followed from that that 1(/1+v^2)dv = 1/(1+u^2)du and made very little progress after that
Q7) I showed the very first part. I then found dy/dx in terms of t but couldn't show that an equation in t would equal zero. However, from there I deduced the equation relating to the determinant and successfully wrote down the geometric interpretation being two tangents intersecting at one point. I then successfully sketched the cases where X^2=a^2 (one graph showing X=a and the other showing X=-a). I then managed to successfully arrive at the values of pq, which you had to show, and then p+q. After this I moved on
Q8) I showed the summation series in the stem of the question, however might drop 1 mark as I wasn't very clear towards the end. I showed the first part completely correctly, but didn't go on to do the second.

That's all I answered. What do you reckon my mark breakdown will be, and do I stand a reasonable chance of getting a 1 in this paper?

Thanks

1) 20, or if less then 20 that's for you to decide.
3) I'd say finding the roots in the last part was at least 10 marks; you're not giving much to go on, but I'm going to guess you lost most of the marks for this. 13?
4) Again, the DE in f+g is going to a lot of marks. 12?
5) 20
6) 16
8) 8

So 89 or so.

thank you! clarifying for 3: I got upto a correct quadratic (in a very not neat way) that had 1 pair of the roots, but solved this wrong (exam pressure...), and thought i could just use the relationship ab=5 to find the other two roots, but this was incorrect as the roots which i found were y/d (and not a or b); hence the "only 1 pair of roots with an arithmetic error".

Q1) 18 assuming you're right that this was the only error.
Q3) either 1 or 0, to be honest.
Q5) I'm finding it hard to see how what you've written for r matches the TSR solution. I think you may have lost more than you think, but it's really impossible to tell from what you've written. 15?
Q6) 8?
Q7) 11?
Q8) 12?

So a total of maybe 64.

For 5 if you multiply top and bottom by cos^2(theta) it's the same as the solution, I got this as well