ATAR Notes: Forum

Archived Discussion => Mathematics/Science/Technology => 2015 Exam Discussion => Specialist Mathematics => Topic started by: bobisnotmyname on November 09, 2015, 05:43:06 pm

Title: Specialist Exam 2
Post by: bobisnotmyname on November 09, 2015, 05:43:06 pm
Thought I might start the discussion :), I found it quiet hard, multiple choice killed me  :-\
Title: Re: Specialist Exam 2
Post by: grannysmith on November 09, 2015, 05:45:36 pm
I thought it was a rather accessible exam - it had a lot in common with past exams I think.

But yeah, I spent 30-35 mins on MC :/  What does everybody think the cut-off will be? 70-71/80?
Title: Re: Specialist Exam 2
Post by: GeniDoi on November 09, 2015, 05:49:56 pm
Thought it was quite manageable. MC was a little tidious but allg
Title: Re: Specialist Exam 2
Post by: Splash-Tackle-Flail on November 09, 2015, 05:51:57 pm
Well I got destroyed... Left 2 pages blank, not cause of time, cause I had no idea whatsoever how to solve the Qs :/

ggwpspesh2k15
Title: Re: Specialist Exam 2
Post by: Orb on November 09, 2015, 05:55:58 pm
the amount of hidden tricks is ridiculous

I'd hope that it's something like 65-68/80 simply because I can't see anyone 22/22ing m.c and the last er was quite tough
Title: Re: Specialist Exam 2
Post by: Escobar on November 09, 2015, 06:00:03 pm
for the last question, were we supposed to integrate dt/dv? i accidentally did dv/dt, how many marks would i lose?
Title: Re: Specialist Exam 2
Post by: Matt97 on November 09, 2015, 06:02:41 pm
Anyone got a copy of the exam to upload?  :)
Title: Re: Specialist Exam 2
Post by: zyzz101 on November 09, 2015, 06:02:52 pm
In scaling we trust.....
Title: Re: Specialist Exam 2
Post by: keltingmeith on November 09, 2015, 06:09:27 pm
Don't worry, guys - the exam 2s have a history of either going really well, or really shit. Usually in about a 1:99 split. :P

Legit, tho, this is probably the toughest exam you'll do - don't stress about not doing as well in it, particularly with MC! (remember: each MC is only worth 1 mark on the /80 scale)
Title: Re: Specialist Exam 2
Post by: GeniDoi on November 09, 2015, 06:18:11 pm
the amount of hidden tricks is ridiculous

I'd hope that it's something like 65-68/80 simply because I can't see anyone 22/22ing m.c and the last er was quite tough

Holy shit, that question 3 was a fuckball. I was tossing between D and E for ages and ended up going with E (multiple lines) because getting a single line would be possible if a = 1. Well turns out, if a = 1, you get two solutions for vertical lines (and a similar story for horizontal lines) so it's fucking D.

Then that vector sum question involving tension forces that were vectors... lol... you could see VCAA crushing the balls of anyone that didn't pay attention to those tildas.
Title: Re: Specialist Exam 2
Post by: Floatzel98 on November 09, 2015, 06:19:15 pm
Well I am pretty happy with how I did in extended response. I at least completed all the questions pretty confidently, so thats something. The only one I didn't know how to do (until the last minute) was the last part of the complex number question. I had no idea how to get the roots into polar form. Other than that I thought that part of the test was pretty good. The multiple choice was a pain though. I spent only 10 minutes on it at the start and skipped about 15 questions. When I went back after I finished section B I still ended up guessing like 3.
Title: Re: Specialist Exam 2
Post by: GeniDoi on November 09, 2015, 06:21:29 pm
Well I am pretty happy with how I did in extended response. I at least completed all the questions pretty confidently, so thats something. The only one I didn't know how to do (until the last minute) was the last part of the complex number question. I had no idea how to get the roots into polar form. Other than that I thought that part of the test was pretty good. The multiple choice was a pain though. I spent only 10 minutes on it at the start and skipped about 15 questions. When I went back after I finished section B I still ended up guessing like 3.

I just quadratic formula'd it and the discriminant turned out to be 16cos(theta)^2 - 16. If you take a negative out you end up with sqrt(-16(1-cos(theta)^2))
= 4sqrt(-sin(theta)^2)
= 4sin(theta) * sqrt(-1)
= 4i*sin(theta).
Title: Re: Specialist Exam 2
Post by: bobisnotmyname on November 09, 2015, 06:21:46 pm
I think it was a smart for me to do multiple choice last, no joke I guessed about 15 of them (educated). I either had no idea or didn't want to waste time getting the one mark
Title: Re: Specialist Exam 2
Post by: Orb on November 09, 2015, 06:23:30 pm
I just quadratic formula'd it and the discriminant turned out to be 16cos(theta)^2 - 16. If you take a negative out you end up with sqrt(-16(1-cos(theta)^2)) = 4sqrt(-sin(theta)^2)=4sin(theta) * sqrt(-1) = 4i*sin(theta)

Pretty sure you could've just solved the entire equation via cas for a really nice 2cis(a) and 2cis(-a) :)
Title: Re: Specialist Exam 2
Post by: GeniDoi on November 09, 2015, 06:26:15 pm
Pretty sure you could've just solved the entire equation via cas for a really nice 2cis(a) and 2cis(-a) :)

I was talking about how to get the imaginary part of the root - the real part is obviously just 4cos(a) (the -b in the quadratic formula), so the whole expression is

(4cos(a) +- 4sin(a)i)/2 = 2cis(+-a) like you said,

BTW, what was a for the question below that one?
Title: Re: Specialist Exam 2
Post by: appleandbee on November 09, 2015, 06:36:40 pm
I was fine with the last question because there was something similar in one of the 2011/2012 exams. The extended response was decent in my opinion (nothing too ambiguous), but some of the multiple choice questions were a bit dodgy. There was one with the slope fields where I traced out a solution curve that didn't match any of the points.
Title: Re: Specialist Exam 2
Post by: lena36 on November 09, 2015, 06:38:29 pm
does anyone have answers to the exam? or the mcs

thanks :)
Title: Re: Specialist Exam 2
Post by: Orb on November 09, 2015, 06:45:33 pm
I was talking about how to get the imaginary part of the root - the real part is obviously just 4cos(a) (the -b in the quadratic formula), so the whole expression is

(4cos(a) +- 4sin(a)i)/2 = 2cis(+-a) like you said,

BTW, what was a for the question below that one?
5pi/12
Title: Re: Specialist Exam 2
Post by: wobblywobbly on November 09, 2015, 06:54:17 pm
Gahhhhh! After getting a perfect score in Exam 1 its a crash out now... Lost at least ten marks now... I thought this was harder than any other VCAA exam I've ever done...
Title: Re: Specialist Exam 2
Post by: Splash-Tackle-Flail on November 09, 2015, 06:56:17 pm
Gahhhhh! After getting a perfect score in Exam 1 its a crash out now... Lost at least ten marks now... I thought this was harder than any other VCAA exam I've ever done...

me too man (minus aceing exam 1)... Out of all the VCAA papers I did (2006-2014), I've never felt so destroyed.. 

5pi/12


That's what I got- but in hindsight, wouldn't -5pi/12 work too, cause of the modulus?
Title: Re: Specialist Exam 2
Post by: lomonm10 on November 09, 2015, 06:59:29 pm
me too man (minus aceing exam 1)... Out of all the VCAA papers I did (2006-2014), I've never felt so destroyed.. 

That's what I got- but in hindsight, wouldn't -5pi/12 work too, cause of the modulus?

I also wrote 5pi/12, the question asked what is the value of a, not values so surely if you just write 5pi/12 you get the mark
Title: Re: Specialist Exam 2
Post by: GeniDoi on November 09, 2015, 07:00:18 pm
That's what I got- but in hindsight, wouldn't -5pi/12 work too, cause of the modulus?

Na because a needs to be in the domain 0<= a <= pi/2
Title: Re: Specialist Exam 2
Post by: Splash-Tackle-Flail on November 09, 2015, 07:00:47 pm
I also wrote 5pi/12, the question asked what is the value of a, not values so surely if you just write 5pi/12 you get the mark

Yeah  upon rereading it it said a is from 0 to pi/2; now here's the thing, I literally guessed 5pi/12 in the last 20 seconds of the exam, would I get the mark if I didn't dismiss -5pi/12? !!! :D
Title: Re: Specialist Exam 2
Post by: bobisnotmyname on November 09, 2015, 07:01:16 pm
I don't want to annoy people too much with study score predictions, but do you think 90/120 would get a 35
Title: Re: Specialist Exam 2
Post by: bobisnotmyname on November 09, 2015, 07:02:30 pm
Yeah  upon rereading it it said a is from 0 to pi/2; now here's the thing, I literally guessed 5pi/12 in the last 20 seconds of the exam, would I get the mark if I didn't dismiss -5pi/12? !!! :D
it was only one mark wasn't it. if so only the answer gets you the mark, so yes you will definitely get the mark
sorry I missed read you post, if you included the other value you would probabily lose the mark sorry man
Title: Re: Specialist Exam 2
Post by: Orb on November 09, 2015, 07:03:22 pm
Yeah  upon rereading it it said a is from 0 to pi/2; now here's the thing, I literally guessed 5pi/12 in the last 20 seconds of the exam, would I get the mark if I didn't dismiss -5pi/12? !!! :D

You'd lose it :( You don't get any answer marks if you write a wrong answer
I don't want to annoy people too much with study score predictions, but do you think 90/120 would get a 35

Probably :P
Title: Re: Specialist Exam 2
Post by: GeniDoi on November 09, 2015, 07:06:09 pm
t=0.9s for the last one?
Title: Re: Specialist Exam 2
Post by: bobisnotmyname on November 09, 2015, 07:09:23 pm
did any one find the acceleration or something in one of the questions to 3 decimal places to be something like 0.600, like the last two digits zeros.
Title: Re: Specialist Exam 2
Post by: grannysmith on November 09, 2015, 07:10:48 pm
t=0.9s for the last one?
Yeah that's what I got.

What did people get for the inverse function? That was some pretty weird stuff
Title: Re: Specialist Exam 2
Post by: alchemy on November 09, 2015, 07:10:55 pm
After a perfect score in exam 1, I reckon I lost 10 marks all up on this.., not sure if that gives 45 raw but oh well such is life :(
Found it to be on par with most years except a tad bit more time consuming tbh.
Title: Re: Specialist Exam 2
Post by: GeniDoi on November 09, 2015, 07:12:31 pm
did any one find the acceleration or something in one of the questions to 3 decimal places to be something like 0.600, like the last two digits zeros.

I got a = 0.902? For the inclined plane question?
Title: Re: Specialist Exam 2
Post by: the_analyser on November 09, 2015, 07:13:38 pm
I got a = 0.902? For the inclined plane question?
Same here
Title: Re: Specialist Exam 2
Post by: schooliskool on November 09, 2015, 07:13:43 pm
2014 was literally nothing compared to this years one lol

Didn't go bad but wasn't great, I found the mcq hard af though
Title: Re: Specialist Exam 2
Post by: TiffanyF01 on November 09, 2015, 07:18:30 pm
I got a = 0.902? For the inclined plane question?
ME TOO thankgod
Title: Re: Specialist Exam 2
Post by: bobisnotmyname on November 09, 2015, 07:19:18 pm
I got a = 0.902? For the inclined plane question?
that must have been it, dam I knew something wasn't right haha
Title: Re: Specialist Exam 2
Post by: Splash-Tackle-Flail on November 09, 2015, 07:20:47 pm
You'd lose it :( You don't get any answer marks if you write a wrong answer
Probably :P

Nah I mean like I wrote 5pi/12 but that's it like I didn't write +-5pi/12 then say the negative one is invalid if that makes sense... Aw well ahha

And just realised I got the last question 4 part wrong because I typed in t=25 instead of 45.. How many would they take off for this, considering the mistake was typing it in my calculator wrong?
Title: Re: Specialist Exam 2
Post by: TiffanyF01 on November 09, 2015, 07:21:57 pm
Out of curiosity, what do you guys think Spesh will scale by this year? I didn't think it was too bad (messed up Exam 1 big time though) but since a lot of people found it harder than previous years exam, do you think it will scale more? Unlikely right? Since it already scales so much
Title: Re: Specialist Exam 2
Post by: bobisnotmyname on November 09, 2015, 07:22:44 pm
so does anyone have a copy of the exam?
Title: Re: Specialist Exam 2
Post by: GeniDoi on November 09, 2015, 07:23:22 pm
Out of curiosity, what do you guys think Spesh will scale by this year? I didn't think it was too bad (messed up Exam 1 big time though) but since a lot of people found it harder than previous years exam, do you think it will scale more? Unlikely right? Since it already scales so much

The difficulty of the exam doesn't change the scaling, it changes the mark required on the exam to achieve a raw certain study score. If the exam was more difficult it's possible you might have only needed high 60s/80 to get 40 raw (provided a similar score on exam 1) compared to the 72.5/80 for 2014.

I'm gonna give it the benefit of doubt and say it was slightly more difficult than last years, so it may drop to 70 or even 69, but I doubt it'll go much lower.
Title: Re: Specialist Exam 2
Post by: Orb on November 09, 2015, 07:23:43 pm
Out of curiosity, what do you guys think Spesh will scale by this year? I didn't think it was too bad (messed up Exam 1 big time though) but since a lot of people found it harder than previous years exam, do you think it will scale more? Unlikely right? Since it already scales so much

Should be the same as other years.
It won't scale past 55, that's absurd and 40 won't scale much past 51 because that's suggesting that 40 spesh is harder than 50 basically any other subject
Title: Re: Specialist Exam 2
Post by: bobisnotmyname on November 09, 2015, 07:24:23 pm
Out of curiosity, what do you guys think Spesh will scale by this year? I didn't think it was too bad (messed up Exam 1 big time though) but since a lot of people found it harder than previous years exam, do you think it will scale more? Unlikely right? Since it already scales so much
I could be wrong, but I don't think scaling matters if it was a hard years exams or not, only if the people completing the subject go better in other classes. So probably the same scaling
Title: Re: Specialist Exam 2
Post by: schooliskool on November 09, 2015, 07:25:43 pm
The difficulty of the exam doesn't change the scaling, it changes the mark required on the exam to achieve a certain study score. If the exam was more difficult it's possible you might have only needed high 60s/80 to get 40 raw (provided a similar score on exam 1)
I thought in 2013 the methods one scaled 8 and 2014 only 5, because 2013 was hard? Same with accounting (probs more, just the ones I know of)
Or is it just spesh that has a set scale? Makes sense cos 2014 piss easy exam still scaled 12 at 30/35
Title: Re: Specialist Exam 2
Post by: yeahm8 on November 09, 2015, 07:26:08 pm
Does vcaa give working marks? Eg. The second last complex number question I used quad form and subbed the identity but stopped because I thought I wasn't on the right track. Any chance for a mark?
Title: Re: Specialist Exam 2
Post by: TiffanyF01 on November 09, 2015, 07:27:24 pm
Thank you everyone, that makes so much sense, I didn't realise that difficulty would affect the A+ cut off and not the scaling, which makes sense and is also more fair
THANK YOU  :) :)
Title: Re: Specialist Exam 2
Post by: zsteve on November 09, 2015, 07:30:07 pm
I just quadratic formula'd it and the discriminant turned out to be 16cos(theta)^2 - 16. If you take a negative out you end up with sqrt(-16(1-cos(theta)^2))
= 4sqrt(-sin(theta)^2)
= 4sin(theta) * sqrt(-1)
= 4i*sin(theta).
For that one I just argued that the expression under the radical was negative, so negated that and stuck an i at the end
Title: Re: Specialist Exam 2
Post by: zsteve on November 09, 2015, 07:33:58 pm
And was the final question 0.9?
Title: Re: Specialist Exam 2
Post by: GeniDoi on November 09, 2015, 07:35:09 pm
And was the final question 0.9?

Yep, confirmed a bit before. Tricky question.
Title: Re: Specialist Exam 2
Post by: bobisnotmyname on November 09, 2015, 07:41:40 pm
for the boat trailer question. when it asked for the acceleration to 3 decimal points, I used the approximated answer derived from the first question (to the nearest newton), will I still get full marks or loss mark for that?
Title: Re: Specialist Exam 2
Post by: byCrypt on November 09, 2015, 07:42:57 pm
Multiple choice and that final part of the last question destroyed me. I think I got at least 6 MC wrong. Hardest VCAA exam yet imo.

Do you think 38/40 and 69/80 is still possible for a 40? :-\
Title: Re: Specialist Exam 2
Post by: aahellen290 on November 09, 2015, 07:43:39 pm
please anyone post the paper
Title: Re: Specialist Exam 2
Post by: zsteve on November 09, 2015, 07:45:30 pm
for the boat trailer question. when it asked for the acceleration to 3 decimal points, I used the approximated answer derived from the first question (to the nearest newton), will I still get full marks or loss mark for that?
I'm not sure - I think correct practice is to use calculator values (like in chemistry/physics) when dealing with decimals, although I wouldn't think so unless it rounded correctly (which could be expected, I think sometimes the questions 'lead' you to use previous results, as evidenced by a decreasing number of dec places as you progress through the question)
tl;dr - not sure, although I'd say it would be possible if it rounded correctly.
Title: Re: Specialist Exam 2
Post by: GeniDoi on November 09, 2015, 07:46:50 pm
Multiple choice and that final part of the last question destroyed me. I think I got at least 6 MC wrong. Hardest VCAA exam yet imo.

Do you think 38/40 and 69/80 is still possible for a 40? :-\

I'd put money on it that it is. That was no 2014 exam.
Title: Re: Specialist Exam 2
Post by: HighTide on November 09, 2015, 07:48:09 pm
please anyone post the paper
Isn't Q16 D?? Just not sure.
Title: Re: Specialist Exam 2
Post by: zsteve on November 09, 2015, 07:53:20 pm
Yep, confirmed a bit before. Tricky question.
no- the very last q on the paper - 0.8948 rounded to 0.9
Title: Re: Specialist Exam 2
Post by: cosine on November 09, 2015, 07:54:06 pm
no- the very last q on the paper - 0.8948 rounded to 0.9

i got that too, rounded it to 0.9
Title: Re: Specialist Exam 2
Post by: GeniDoi on November 09, 2015, 07:54:34 pm
no- the very last q on the paper - 0.8948 rounded to 0.9

Yes on page 2. Not talking about the acceleration question.
Title: Re: Specialist Exam 2
Post by: Splash-Tackle-Flail on November 09, 2015, 07:55:54 pm
Yeah that last question... I tried implicit differentiating the expression (took like 15 minutes :( ) and ended up simplifying to dx/dt=v...fml
Title: Re: Specialist Exam 2
Post by: yeahm8 on November 09, 2015, 07:57:52 pm
Does vcaa give working marks? Eg. The second last complex number question I used quad form and subbed the identity but stopped because I thought I wasn't on the right track. Any chance for a mark?
can anyone answer this?
Title: Re: Specialist Exam 2
Post by: cosine on November 09, 2015, 08:00:55 pm
guys for 2a)iv). i correctly subbed in y=equation into the circle formula, but i forgot to square y, to obviously the rest of the working out is wrong... but however i did manage to get the right y values for the incorrect initial x value, and got this in the cartesian form.. would i get 1 mark for this? It was out of 3 marks, could i possible get 2 marks for such an early arithmetic error?
Title: Re: Specialist Exam 2
Post by: bobisnotmyname on November 09, 2015, 08:04:29 pm
for anyone after solutions, they are on the specialist question section
Title: Re: Specialist Exam 2
Post by: Splash-Tackle-Flail on November 09, 2015, 08:16:30 pm
Does anyone think the A+ cutoffs will reflect the 2008 exam?
Title: Re: Specialist Exam 2
Post by: rahul_kumar1998 on November 09, 2015, 08:18:21 pm
Where is this section?
Title: Re: Specialist Exam 2
Post by: HopefulLawStudent on November 11, 2015, 02:53:21 pm
Goodbye to the raw 40 I wanted in Specialist. It was nice knowing you.  :'(

We didn't even get the chance to know each other before you were cruelly ripped away from me.

Seriously. Looking at a 33/34 out of 40 for Exam One and 71/72 out of 80 for Exam Two. Was even the highest rank student going into the exam. Walked into exam one going a 45's a nice number, walked out thinking I've screwed up, I'd be happy with a 40. Now? Ugh. I don't even want to know.
Title: Re: Specialist Exam 2
Post by: Orb on November 11, 2015, 03:03:34 pm
Goodbye to the raw 40 I wanted in Specialist. It was nice knowing you.  :'(

We didn't even get the chance to know each other before you were cruelly ripped away from me.

Seriously. Looking at a 33/34 out of 40 for Exam One and 71/72 out of 80 for Exam Two. Was even the highest rank student going into the exam. Walked into exam one going a 45's a nice number, walked out thinking I've screwed up, I'd be happy with a 40. Now? Ugh. I don't even want to know.

If you dropped 6 + 8 = 14, that could be a 40 raw in some years :) (in 2008 it was 41-42)
Title: Re: Specialist Exam 2
Post by: Splash-Tackle-Flail on November 11, 2015, 04:50:19 pm
Do you think it's possible to get a 43ish based on my prediction on the ss prediction board? I made so many unforced errors, and I can't stop regretting it post mortem style :/ I think the pressure just got to me, and I did mistakes I had told myself to watch out for the night before ugh...
Title: Re: Specialist Exam 2
Post by: HopefulLawStudent on November 11, 2015, 05:07:04 pm
If you dropped 6 + 8 = 14, that could be a 40 raw in some years :) (in 2008 it was 41-42)


... But it won't be. I'm not awfully optimistic. And this exam was 2008 standard. It was easier. I know it was harder than 2014 but personally don't feel it compares to 2008. Hence why I am not enthusiastic.

Do you think it's possible to get a 43ish based on my prediction on the ss prediction board? I made so many unforced errors, and I can't stop regretting it post mortem style :/ I think the pressure just got to me, and I did mistakes I had told myself to watch out for the night before ugh...

You did better than me. If you're not getting a 43ish, I'm screwed atar-wise. More than I knew I already was, anyway.

Do you want my honest opinion for your study score?

Spoiler
"No one can really predict your SS. Anyone who thinks they can is either deluded, guessing or just throwing a number at you to appease you. Ultimately, the only SS that matters is the one you get on December 14. So in the mean time, catch up on sleep, recycle past exams, place your faith in scaling and pray. That is all you can do. Knowing now won't make a difference to knowing in a month. I know you don't realise it but... Ultimately, your study score is just a number. Ultimately, your ATAR is just a number. And there is so much more to you than a number." - My Specialist Teacher

For me, personally, time was a really big issue. It just felt like there was not enough time. I did the ER first and I am totally glad I did. There were more marks to be found there than MC's but I just didn't have enough time to go back and check so I could eradicate any dumb mistakes + that verrrry last question in the ER with the definite integral + some of the MC's were plain nasty.  :-\ :'(
Title: Re: Specialist Exam 2
Post by: Splash-Tackle-Flail on November 11, 2015, 05:15:35 pm
... But it won't be. I'm not awfully optimistic. And this exam was 2008 standard. It was easier. I know it was harder than 2014 but personally don't feel it compares to 2008. Hence why I am not enthusiastic.

You did better than me. If you're not getting a 43ish, I'm screwed atar-wise. More than I knew I already was, anyway.

Do you want my honest opinion for your study score?

Spoiler
"No one can really predict your SS. Anyone who thinks they can is either deluded, guessing or just throwing a number at you to appease you. Ultimately, the only SS that matters is the one you get on December 14. So in the mean time, catch up on sleep, recycle past exams, place your faith in scaling and pray. That is all you can do. Knowing now won't make a difference to knowing in a month. I know you don't realise it but... Ultimately, your study score is just a number. Ultimately, your ATAR is just a number. And there is so much more to you than a number." - My Specialist Teacher

For me, personally, time was a really big issue. It just felt like there was not enough time. I did the ER first and I am totally glad I did. There were more marks to be found there than MC's but I just didn't have enough time to go back and check so I could eradicate any dumb mistakes + that verrrry last question in the ER with the definite integral + some of the MC's were plain nasty.  :-\ :'(

Yeah that's true haha <3 Thanks, I think I needed that :)

All the best for you too!