2014 HSC Extension 2 Maths Carrotsticks' Solutions (2 Viewers)

[iStudent]

For 12ai the left side of the graph. Shouldn't it be concave down?
Or is it you can't tell :s
I hope I don't lose marks for making it smooth+concave down

 

[IR]

I feel extremely depressed. My dreams of 98 aligned/scaled were shattered despite my hard work since the last term of Year 11, where I have given 10x the time for four unit then other subjects. What do you guys reckon does a raw 88-90 scale/align to

 

[IR]

For 12ai the left side of the graph. Shouldn't it be concave down?
Or is it you can't tell :s
I hope I don't lose marks for making it smooth+concave down

I made concave down but not smooth. I made an open circle and broke off more towards negative infinity.

 

[Sy123]

I feel extremely depressed. My dreams of 98 aligned/scaled were shattered despite my hard work since the last term of Year 11, where I have given 10x the time for four unit then other subjects. What do you guys reckon does a raw 88-90 scale/align to

Bad luck man
Just don't let it get you down for other subjects!

I think 88-90 would scale to 97, but I am no expert

 

[enigma_1]

I feel extremely depressed. My dreams of 98 aligned/scaled were shattered despite my hard work since the last term of Year 11, where I have given 10x the time for four unit then other subjects. What do you guys reckon does a raw 88-90 scale/align to

That's crazy good, why are you worried?

Roughly 96-97.

 

[mreditor16]

Bad luck man
Just don't let it get you down for other subjects!

I think 88-90 would ALIGN to 97, but I am no expert

that would happen, if last year's aligning is an indicator

 

[Sy123]

that would happen, if last year's aligning is an indicator

wow I made such a noob error

what have I become

 

[IR]

Bad luck man
Just don't let it get you down for other subjects!

I think 88-90 would scale to 97, but I am no expert

Thanks man. Before exam I was aiming for 98 raw but after was aiming for 98 scaled and now I see that got 5/10 for multiple choice due to mistakes in seeing the option correctly and was my major downfall. Almost 10 marks of careless. Math is my life and feels like I lost it.

 

[obliviousninja]

 

[alex4nder]

Thanks heaps for your hard work carrotsticks!

 

[emilios]

i can't actually believe people are complaining that they got low 90s raw. i know we all have different goals and ambitions but you do realise that the difference that a 96 vs 98 in 4U makes on your atar is like minimal?

 

[faisalabdul16]

i can't actually believe people are complaining that they got low 90s raw. i know we all have different goals and ambitions but you do realise that the difference that a 96 vs 98 in 4U makes on your atar is like minimal?

haha exactly what I think! Hence why Im fine with a 93 HSC mark (that's what i believe ill get) despite it could have been higher if i didn't make stupid sillies.

 

[aDimitri]

i can't actually believe people are complaining that they got low 90s raw. i know we all have different goals and ambitions but you do realise that the difference that a 96 vs 98 in 4U makes on your atar is like minimal?

look i understand this but personally my atar requirement isn't an issue in the slightest and i couldn't care less about maximizing my atar, if i did i would have at least prepared a related text for english. i care more about doing well in the subjects i enjoy the most, which happens to be 4U. hence disappointment.

 

[IR]

look i understand this but personally my atar requirement isn't an issue in the slightest and i couldn't care less about maximizing my atar, if i did i would have at least prepared a related text for english. i care more about doing well in the subjects i enjoy the most, which happens to be 4U. hence disappointment.

Exactly why. 4U is my life. If I dont get the equivalent reward for my effort, then what good is an effort.

 

[iStudent]

I personally only did 07-13 papers and I have no regrets
I'm kind of questioning why people emphasise so much on past papers :/ (unless you want to reach state rank)
(although I got plenty of harder question exposure by getting tutoring)

 

[Tugga]

Also, for the angle between two lines, I didn't get rid of absolute values. Can somebody clarify?

I talked about how the ellipse is symmetric around x and y-axis, so the problem can always be transformed into a theta such that 0<=theta<=pi/2.

Not sure if it was required/legit though :L

 

[mreditor16]

I personally only did 07-13 papers and I have no regrets
I'm kind of questioning why people emphasise so much on past papers :/ (unless you want to reach state rank)
(although I got plenty of harder question exposure by getting tutoring)

same especially the bolded part

 

[braintic]

Exactly why. 4U is my life. If I dont get the equivalent reward for my effort, then what good is an effort.

If you really like maths, then the effort is the reward.
(Or at least ONE of the rewards)

 

[faisalabdul16]

I personally only did 07-13 papers and I have no regrets
I'm kind of questioning why people emphasise so much on past papers :/ (unless you want to reach state rank)
(although I got plenty of harder question exposure by getting tutoring)

same especially the bolded part

Mreditor! Bold part, think about tutorial booklets. Hahahahahaha all them weird yet cool questions.

 

[Carrotsticks]

BTW carrot for 15c) iii) where you have to show increasing function is it valid to show in equivalent of sin theta/cos^2theta in terms of v, where derivative of both sides in respect to v gives 2lg/v^3, where v>0 for v>0 considering cos theta is even function which is >0 for -pi/2<theta<pi/2

That can't work without the chain rule because theta depends on v.

Would you get 1 mark if you just did substitution and did the +1 -1 trick but then you didn't get the final answer? (I wrote 3 booklets of junk in hope to scab marks). It seems awkward it's 3 marks allocated for what, 4 lines? lol

If that's all you did, perhaps if you're lucky.

your justification for question 2 although valid, is probably not the most effective way to do it.
I did it by difference of two squares or something like that.

What question was this? I don't remember. Not at home.

For 12ai the left side of the graph. Shouldn't it be concave down?
Or is it you can't tell :s
I hope I don't lose marks for making it smooth+concave down

Not enough information to tell because it depends on the curvature. For example, if it looked like y=1/cuberoot(x), then it would diverge slowly but if it looked like y=1/x^3, then that diverges quickly.