Carrotsticks' Solutions 2015 Extension 1 HSC (4 Viewers)

[Carrotsticks]

For q11e, it said evaluate, i left my answer in 2.decimal places, got 0.44, will i lose a mark?

If you still had the correct exact value and THEN threw it in the calculator for your final line, you would've gotten 3 marks still.

 

[Trebla]

For those asking about state ranks, they consider your Ext2 (or 2U) marks to break ties for Ext1. Also, if I'm not mistaken where there are ties in the final HSC mark but the HSC external marks differ then the external mark is used to break the tie.

 

[kawaiipotato]

For Q13 (a) (iii)
Instead of using the previous parts (or using SHM properties), was it fine to just let v^2 = b(x-3)(x-7) (since they said it was a parabola)
Subbing (5,11)
giving b = -11/4 ==> v^2 = -11/4 (x-3)(x-7)
v^2 = 11/4 (4 - (x-5)^2) and equating?

 

[Carrotsticks]

For Q13 (a) (iii)
Instead of using the previous parts (or using SHM properties), was it fine to just let v^2 = b(x-3)(x-7) (since they said it was a parabola)
Subbing (5,11)
giving b = -11/4 ==> v^2 = -11/4 (x-3)(x-7)
v^2 = 11/4 (4 - (x-5)^2) and equating?

That is also valid, and an excellent method too.

 

[ENFP]

Given that I'm doing 4U in the 2016 HSC (I accelerated 2U and 3U), and I need an ATAR of 99+, what's the lowest scaled/adjusted result I can afford to have for 3U, assuming I get top-end B6s in all my subjects next year? (SDD, Ancient History, English Adv., Physics, 4U Maths) If a borderline or low-end E4 will stop me from getting my required ATAR I'm prepared to redo 3U. If it contributes anything, my expected raw in 2U is 98/99%. Idk if this is the right place to ask but gotta be in it to win it, right?

 

[atargainz]

Given that I'm doing 4U in the 2016 HSC (I accelerated 2U and 3U), and I need an ATAR of 99+, what's the lowest scaled/adjusted result I can afford to have for 3U, assuming I get top-end B6s in all my subjects next year? (SDD, Ancient History, English Adv., Physics, 4U Maths) If a borderline or low-end E4 will stop me from getting my required ATAR I'm prepared to redo 3U. If it contributes anything, my expected raw in 2U is 98/99%. Idk if this is the right place to ask but gotta be in it to win it, right?

Assuming you get top end band 6s in everything else (96+), you can get an E3 in Ext 1 and still get 99+. 99.95 is a different story though

 

[ENFP]

Assuming you get top end band 6s in everything else (96+), you can get an E3 in Ext 1 and still get 99+. 99.95 is a different story though

Tell me that story please xD
Also this is gonna come across as hella arrogant, but say in hypothetical dreamland I get state ranks in Physics, Software and 4U Maths, would I then be able to get 99.95 with a mid/low end E4 in 3U Maths?

 

[luhanbby]

for the limiting solution I wrote x -> 1 but I didn't say at the end x = 1. Is that going to cost me a mark?


Sent from my iPhone using Tapatalk

 

[Carrotsticks]

for the limiting solution I wrote x -> 1 but I didn't say at the end x = 1. Is that going to cost me a mark?


Sent from my iPhone using Tapatalk

Definitely not.

My solutions are by no means intended to be the solutions I were to put in if I were doing the exam myself.

I've made them intentionally more elaborate etc for the benefit of students doing the HSC in future years reading my solutions to learn!

 

[Drsoccerball]

Could the markers take off a mark for not sketching the circle in question 12 as it was stated:/

 

[joshua270897]

For 14c ii), will I lose a mark if I used 5C5 instead of 4C4?

 

[Carrotsticks]

Could the markers take off a mark for not sketching the circle in question 12 as it was stated:/

No.

They ask you to copy/trace it so you have a diagram to work with, and so they can refer to your diagram if you've made any labels etc and used them in your solution without first defining them explicitly.

 

[Carrotsticks]

For 14c ii), will I lose a mark if I used 5C5 instead of 4C4?

If everything else was correct, then no you would have not lost a mark. It is a 1 mark question only. Docking you for that categorises you in the same class as students who did not attempt the question, which is of course ridiculous.

 

[Ekman]

Hey carrot, other than mathtype, are there any other programs that write up math equations?

 

[Drsoccerball]

Hey carrot, other than mathtype, are there any other programs that write up math equations?

a.k.a any free programs?

 

[ENFP]

Carrot, you changed the answer for 12diii back to 7.83... Why isn't it 2.57?

 

[Carrotsticks]

Carrot, you changed the answer for 12diii back to 7.83... Why isn't it 2.57?

That's strange. I didn't edit it back, so not sure why it decided to do that.

Anyway, I'll fix it now, cheers for pointing that out.

 

[SNT k]

for question 7 in multiple choice shouldnt the answer by B since its k/2=root(3)/2 therefore k=root(3)?

 

[Drsoccerball]

for question 7 in multiple choice shouldnt the answer by B since its k/2=root(3)/2 therefore k=root(3)?

Use wolfram and see

 

[Carrotsticks]

for question 7 in multiple choice shouldnt the answer by B since its k/2=root(3)/2 therefore k=root(3)?

I fixed that up a few minutes ago. Cheers for pointing it out anyway!