BoS Trials Maths, Physics and Business Studies 2023 (1 Viewer)

Trebla

Trebla

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......and here are the results and solutions for the 2023 Mathematics Extension 2 BoS Trials! 🔥 🔥🔥

Please also note that the question paper has been updated (which these solutions are aligned to) with some minor adjustments to a few questions (e.g. edited some wordings and mark allocations). The updated file is attached in my original post of the papers to replace the older version.

In terms of results, congrats to the the student who scored the top mark of 68! We also had one student score full marks in the multiple choice section and another score full marks in Q12.

Should go without saying, but once again to remind everyone:
Note: These are not your average trial papers. These papers are heavily skewed towards the more challenging questions (i.e. filtered out most of the boring/repetitive easy stuff in a typical trial paper). Students who may be worried about losing motivation after attempting the paper are reminded that this is NOT intended to be an accurate reflection of the difficulty of the HSC exam itself.
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We are continuing to work through the remaining subjects, so please be patient...
 

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scaryshark09

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wow 68 is impressive
any chance this person wants to reveal themselves?
 
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NoctNight

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Trebla said:
......and here are the results and solutions for the 2023 Mathematics Extension 2 BoS Trials! 🔥 🔥🔥

Please also note that the question paper has been updated (which these solutions are aligned to) with some minor adjustments to a few questions (e.g. edited some wordings and mark allocations). The updated file is attached in my original post of the papers to replace the older version.

In terms of results, congrats to the the student who scored the top mark of 68! We also had one student score full marks in the multiple choice section and another score full marks in Q12.

Should go without saying, but once again to remind everyone:


We are continuing to work through the remaining subjects, so please be patient...
Click to expand...
my (first letter of lphbet) key doesnt work nymore but cool pper nd cool questions ngl thx for hosting this every yer tkes lot of effort nd for free s well, wish i ws more prepred sdge
 
Kiiyu

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Wow I really made that many silly mistakes (3/15 q11 💀 ) I really should've gotten 60+ I wonder what I did wrong in q11. Will take the only other pass though ig /shrug.
 
yanujw

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Some part-by-part commentary for Q14

(a) (i) Done well by almost everyone, with only a few silly mistakes here and there. I was surprised that some students could just look at the question and then write the result, but good for you I guess and you did receive the mark. Keep in mind that if that were a 2-mark question in the HSC, simply writing the answer and quoting "by inspection" or "cover-up rule" would almost certainly make you lose a mark.

(ii) The t-formula substitution was successful by everyone and so almost everyone reached the correct anti-derivative of . The part most students could not accomplish was converting this back to the form required in the RHS, which may have felt unfamiliar as you work from a more simplified form to a more complicated expression, while almost every other question is doing the opposite. A number were able to use the double-angle formulae and reach the result, but a particularly clever method used by some students was to leave the primitive in terms of t and then write the RHS in terms of t and show equivalence

(iii) The auxiliary angle conversion and integration of secant was mostly fine. Again, the loss of marks was mainly due to not being able to correct the primitive into the correct form. A number of students made the mistake of calculating alpha and writing it to a few decimal places, which is absolutely not good practice for any question unless it is asked for, much less an indefinite integral which shows you that your answer must be left in terms of trig functions.

(iv) Many students needed a much better understanding of how constants of integration are to be dealt with. Some of the incorrect methods that were frequently used included just cancelling out and , thinking that both the constants were something to each be solved for in the original primitives, or saying that they are negligible or just shift the function up. The correct method was to show that equating primitives results in them differing by a new constant, and then to test that constant by substituting a value of x.

(b) (i) Almost all students recognised the use of roots of unity or the sum of a geometric sequence and wrote the roots in a general exponential form as required.

(ii) As mentioned in a previous comment, this question really stumped everyone. Most people just wrote "product of roots =" or performed a substitution into P(x) to get something of use, to no avail.

(c) (i) Where possible, I recommend students draw the forces on P and Q to illustrate how you derive relationships between T, N and acceleration. It was clear some students couldn't get the result because they were unfamiliar with inclined planes and so missed out on key information, such as the fact that is the angle between N and the upward direction, but otherwise there were few silly mistakes by students that understood how to resolve the forces.

(ii) Very few students got 2/2 for this part, and a majority made no attempt. Most students attempted substitutions of the data given in the question but could not form inequalities - because they weren't properly considering different cases and the dynamics of the situation (i.e. what happens if force is up or down the slope, and how does that form both ends of the inequality). I believe most students were thinking that both ends of the inequality arise from 1 equation, when in fact there are 2 cases to be considered.



Good luck to everyone for Monday!
 
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