2014 BOS Trial Extension 1 Exam Results Thread (2 Viewers)

[Carrotsticks]

Feel free to share your marks, where you messed up or where you did well! Myself and Trebla will be here to answer questions about your paper, especially if you scored something you did not expect. We can explain briefly in this thread (do NOT PM us about this) why you lost the marks.

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Hi all,

Once again, we have completed another year for our series of examinations. The results are out and are attached below.

To find out what mark you or your friends acquired, please message me and I will tell you which rank number you are for your raw mark breakdown.

Congratulations to ALL who attempted the paper and were brave enough to sit it out. You all knew what you were potentially up against, yet you still signed up for it. For that, I would like to commend everybody.

Many students claimed that this was a lot harder than last years, which was reflected in the marks. The highest score was 55/70, as opposed to last year's 65/70.

This exam is designed to differentiate between students aiming for an E4. It is pretty much given that all candidates ARE already safely in the E4 range. The question now is, by how much? This paper separates those from low E4 to a State Rank in Extension 1 Mathematics.

Again, well done all and good luck for your HSC Examinations =)

Here is a copy of the examination. Please note that it is slightly different to the actual exam, as we have corrected any minor issues with the exam paper.

Extension 1 Examination

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[aDimitri]

so much harder than last years.
i would also like a PM for this one thanks

 

[mirachael]

School trials- 100%
BOS trials- 51%

Dem Catherine Deveny feels are strong.

 

[Tugga]

Did they not accept auxilliary angle method for the projectile in q16?

Like converting the sin+cos into a single one to find the max...

 

[aDimitri]

School trials- 100%
BOS trials- 51%

Dem Catherine Deveny feels are strong.

school weighted average mark: 99%
bos mark: 61%
them feels

 

[clockworkorange]

full marked q 11

 

[Tugga]

full marked q 11

How do you do the external interval one?

 

[Carrotsticks]

Any questions anybody?

 

[Carrotsticks]

How do you do the external interval one?

You needed to let the ratio be K:1 and then solve for K, then let that be less than zero.

A lot of students let the ratio be M:N which is technically correct, but then they would have to make M/N the subject (I don't think many people realised this), so letting it be M:N was the downfall of many students.

Do you know why we can let it be K:1 instead of M:N?

 

[Tugga]

You needed to let the ratio be K:1 and then solve for K, then let that be less than zero.

A lot of students let the ratio be M:N which is technically correct, but then they would have to make M/N the subject (I don't think many people realised this), so letting it be M:N was the downfall of many students.

Do you know why we can let it be K:1 instead of M:N?

Ohhh because k doesn't have to be an integer right

 

[aDimitri]

You needed to let the ratio be K:1 and then solve for K, then let that be less than zero.

A lot of students let the ratio be M:N which is technically correct, but then they would have to make M/N the subject (I don't think many people realised this), so letting it be M:N was the downfall of many students.

Do you know why we can let it be K:1 instead of M:N?

this is what i realised straight after the exam.
i did m:n

 

[aDimitri]

i pmed carrot asking which one i was

wot

 

[clockworkorange]

wot

sorry i misinterpreted the statement

 

[Tugga]

Any questions anybody?

I thought I got the projectile one out using auxiliary angle and the fact that arctan(1/x) + arctan (x) =π/2, was this an accepted method and did I just make too many assumptions or something?

 

[clockworkorange]

You needed to let the ratio be K:1 and then solve for K, then let that be less than zero.

A lot of students let the ratio be M:N which is technically correct, but then they would have to make M/N the subject (I don't think many people realised this), so letting it be M:N was the downfall of many students.

Do you know why we can let it be K:1 instead of M:N?

i must admit i did it a different way. i used m and n to get a pair of simultaneous expressions (m, n >0, m - n =/= 0), then did x0/y0 in terms of x1, x2, y1, y2. i then cross multiplied and collected like m and n's, so that m(x0y2-x2y0) = n(x0y1-x1y0).
i then multiplied both sides by (x0y1-x1y0) and divided by m so that (x0y1-x1y0)(x0y2-x2y0) = n/m (x0y1-x1y0)^2 > 0 as required

 

[Carrotsticks]

I thought I got the projectile one out using auxiliary angle and the fact that arctan(1/x) + arctan (x) =π/2, was this an accepted method and did I just make too many assumptions or something?

Had another look at your Q14.

Not sure why it was given a score of 0 on the front page even though you were awarded marks on the inside.

My sincere apologies for this, you have scored an extra 6 marks in Extension 1 and are now ranked 4th. Well done.

However, having a look at your work, it was incredibly difficult figuring out what you tried to do and I had to read it several times to understand your flow of logic. I advise that in the HSC, you make it a lot more clear what you're doing =)

 

[Tugga]

Had another look at your Q14.

Not sure why it was given a score of 0 on the front page even though you were awarded marks on the inside.

My sincere apologies for this, you have scored an extra 6 marks in Extension 1 and are now ranked 4th. Well done.

However, having a look at your work, it was incredibly difficult figuring out what you tried to do and I had to read it several times to understand your flow of logic. I advise that in the HSC, you make it a lot more clear what you're doing =)

Wowowow my privacy carrotsticks :'(.

Haha nah just kidding. Thats cool, I was already satisfied with passing anyway

Yeah, will keep that in mind, was just rushed for time etc. Thanks again!

 

[Carrotsticks]

Note that the table is still the same though. Next year I will be implementing a better system with student ID's.

 

[WhoStanLeee]

PM Please?

 

[Kurosaki]

Trebla the Great is still working on them; be patient, you have 6 days, and I'm sure that it'll be done by the weekend.