Post by: RuiAce on October 26, 2016, 01:15:17 pm
We've provided answers below - for detailed solutions, click on the grey dropdown boxes!
We would love to hear how you felt you went on the exam. How did you rate the difficulty of the paper? Do you disagree with any of the answers? Join in on the discussion below.
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Multiple Choice
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Short Answer
Credits to Jake for typing up the other half of the solutions
Question 11
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Final thoughts
Rui
Okay, now that I've actually DONE some of the paper here's what I have to say.
Yeah that circle geometry didn't click in at all. Some may have noticed how that one went up a bit more delayed.
Many of the things were pretty curveball. Binomial theorem wasn't hard but definitely not something you'd expect either. Also I didn't expect locus to be the very last question. Not everything was immediately obvious but it wasn't the worst locus I had seen thus far.
Questions like 12c are tricky. A LOT of this paper was "TRICKY".
I feel like this was harder than 2015 noticeably. But it doesn't feel as bad as 2013 yet.
Jake
That was a seriously brutal paper. It was just consistently kinda difficult, ya know? No particular question was so out of the ordinary that it would have fucked you over, but every question was just that little bit harder than a normal 3U paper, meaning that the overall 'tone' was just absolutely harsh. How did you go? Think any of our answers are a bit off? Let us know your feelings below!
Post by: Zyzyzyzy on October 26, 2016, 04:37:23 pm
Post by: Phillorsm on October 26, 2016, 04:39:19 pm
Time to prep for Phys and Chem haha -_-
The paper certainly wasn't as hard as it could have been!
Post by: bethjomay on October 26, 2016, 04:46:00 pm
Post by: edmododragon on October 26, 2016, 05:10:36 pm
Post by: bethjomay on October 26, 2016, 05:16:48 pm
I have to say, the questions individually weren't too difficult, but I did feel a lot more restrained for time than in any other paper
Yeah, I couldn't believe how fast it went
Post by: doyouevencheeto on October 26, 2016, 05:19:36 pm
Post by: bohimei on October 26, 2016, 05:21:05 pm
Would you say this exam is harder or easier than the 2010 3 unit hsc?looking at the 2010 raw mark alignment, I say it was way easier this time
Post by: ladyofathena on October 26, 2016, 05:22:21 pm
I have to say, the questions individually weren't too difficult, but I did feel a lot more restrained for time than in any other paper
Same. I think I probably lost about 10 marks but I didn't find it particularly difficult, just time consuming.
Post by: RuiAce on October 26, 2016, 05:23:11 pm
Yeah, I couldn't believe how fast it went
I have to say, the questions individually weren't too difficult, but I did feel a lot more restrained for time than in any other paperThat's cause 3U is a 2 hour exam
Well that was awful...
I got destroyedSorry to hear :( Curveball stuff probably hit you then
I'm so happy math is finally over!!Awesome :)
Time to prep for Phys and Chem haha -_-
The paper certainly wasn't as hard as it could have been!
Yeah onto what's next aha
Would you say this exam is harder or easier than the 2010 3 unit hsc?2010 definitely looks harder.
Post by: bohimei on October 26, 2016, 05:34:14 pm
Post by: zdeathbringer on October 26, 2016, 05:55:36 pm
Post by: gabe.ralph on October 26, 2016, 06:02:49 pm
Post by: massive on October 26, 2016, 06:04:54 pm
Post by: jakesilove on October 26, 2016, 06:07:29 pm
Post by: atar27 on October 26, 2016, 06:09:40 pm
Post by: doyouevencheeto on October 26, 2016, 06:18:14 pm
Post by: Blissfulmelodii on October 26, 2016, 06:19:24 pm
Why is the third MC A and not B??
Post by: goandgoo on October 26, 2016, 06:20:18 pm
Post by: likeneverbefore on October 26, 2016, 06:20:50 pm
Post by: jakesilove on October 26, 2016, 06:21:08 pm
I am literally still trying to process that exam... nothing like the past papers i went through.
Why is the third MC A and not B??
Hey! Because that is the expansion of tan(A-B), not tan(A+B), so the answer will be tan(2x-x)=tan(x)
Post by: jakesilove on October 26, 2016, 06:21:47 pm
The solutions are missing the last two parts (iii and iv) of Q14c
Yep! We're writing them out and uploading them as we speak... keep refreshing!
Post by: jakesilove on October 26, 2016, 06:24:18 pm
hey sorry i was wondering why is MC q9 A and not B because at that point gradient is rise over run....therefore f'(1)=f(1)/1 = f(1)......doesn't that mean f'(1) <1?
Hey! Rise over run doesn't work directly for curves like this; the gradient isn't necessarily less than one, just because the function has moved 1 to the right and is less than one up. This is a curve, not a straight line :)
Post by: kevin217 on October 26, 2016, 06:25:34 pm
Post by: Blissfulmelodii on October 26, 2016, 06:38:55 pm
Hey! Because that is the expansion of tan(A-B), not tan(A+B), so the answer will be tan(2x-x)=tan(x)
ohh wow I can't believe I did not notice that. Makes total sense now, wish i had thought that through in the exam hahaha
Post by: antonia98 on October 26, 2016, 06:40:21 pm
Post by: jakesilove on October 26, 2016, 06:50:39 pm
What would a raw mark of 68% scale to?
Hey! There is a raw marks database you can find, and try to work stuff out, but honestly there is no way of knowing how scaling will effect your mark. There's also no point trying to figure it out; you'll get what you get. So, relax, and focus on the rest of your exams! Good luck
Post by: RuiAce on October 26, 2016, 06:54:21 pm
ohh wow I can't believe I did not notice that. Makes total sense now, wish i had thought that through in the exam hahahaSigns are annoying. But important.
Love how the 2003 circle geo question was basically the same as this yearsEh it wasn't identical. But I did realise the similarity after a bit.
The solutions are missing the last two parts (iii and iv) of Q14cTo further onto what Jake said these are now done
hey sorry i was wondering why is MC q9 A and not B because at that point gradient is rise over run....therefore f'(1)=f(1)/1 = f(1)......doesn't that mean f'(1) <1?To further onto what Jake said, note that your method finds the GRADIENT of the line CONNECTING the points (1, f(1)) and (0,0). We want the gradient of the tangent, which doesn't pass through (0,0); this can be checked since that diagram WAS drawn to scale.
Post by: wesadora on October 26, 2016, 07:05:17 pm
I have to say, the questions individually weren't too difficult, but I did feel a lot more restrained for time than in any other paperlol really? It was cool i like it 8) u slow nerd
Post by: hideakianon on October 26, 2016, 07:06:20 pm
Post by: jakesilove on October 26, 2016, 07:20:32 pm
Do you guys know if there can be a penalty if you didn't draw the circle geo diagram?
Look, I actually don't think there would be! It just might piss the markers off a bit, which could have generally detrimental results. But, like, there aren't actually marks allocated to it, despite what the questions indicates.
Post by: huwsername on October 26, 2016, 07:33:54 pm
the answer you've given makes sense, but I thought that 3C1 (1 required left handed) * 17C10 (everyone else) = 58344 would also work. it's about 50-50 among my friends, too. can anyone help put me on the right track?
Post by: Blissfulmelodii on October 26, 2016, 07:42:00 pm
Post by: RuiAce on October 26, 2016, 07:42:30 pm
I can't see why Question 8 isn't D :/You choose 1 out of the three to be left-handed, and then there's double counting.
the answer you've given makes sense, but I thought that 3C1 (1 required left handed) * 17C10 (everyone else) = 58344 would also work. it's about 50-50 among my friends, too. can anyone help put me on the right track?
Let's say persons A, B and C are left handed.
Choose any one out of person, say A, to be left handed.
One possible scenario for the remainder 17 people are B, D, E, F, ...
BUT, instead, choose B to be left handed
"Another" possible scenario for the remainder 17 people are A, D, E, F, ...
But the above two are clearly the same outcome. Hence you have double counted when TWO (or even all THREE) people that are left handed, have been chosen.
Hence the mistake.
Because the question is asking for 'at least one' which also means that two left handed people can be chosen etc. The solution you've provided only accounts for one left handed person, not more than one.Nah the number is too large, not too small. There is no undercounting here. Especially since he claimed to use 17C10
Post by: RuiAce on October 26, 2016, 07:43:20 pm
Just out of curiosity, does scaling work differently depending on whether extension 1 is worth 1 unit or 2?? Or does the amount of units the course is worth not matter in this case?No that impacts on nothing at all.
Post by: jakesilove on October 26, 2016, 07:43:34 pm
Just out of curiosity, does scaling work differently depending on whether extension 1 is worth 1 unit or 2?? Or does the amount of units the course is worth not matter in this case?
Scaling will work exactly the same! In the end, if 3U is worth one unit, your mark out of 100 (or 200?) will just be cut in half; your unit count doesn't effect scaling.
Post by: Blissfulmelodii on October 26, 2016, 07:45:43 pm
Scaling will work exactly the same! In the end, if 3U is worth one unit, your mark out of 100 (or 200?) will just be cut in half; your unit count doesn't effect scaling.
Ahhh okay that makes total sense. Thanks!!
Post by: ladyofathena on October 26, 2016, 07:48:00 pm
You choose 1 out of the three to be left-handed, and then there's double counting.
Let's say persons A, B and C are left handed.
Choose any one out of person, say A, to be left handed.
One possible scenario for the remainder 17 people are B, D, E, F, ...
BUT, instead, choose B to be left handed
"Another" possible scenario for the remainder 17 people are A, D, E, F, ...
But the above two are clearly the same outcome. Hence you have double counted when TWO (or even all THREE) people that are left handed, have been chosen.
Hence the mistake.
Nah the number is too large, not too small. There is no undercounting here. Especially since he claimed to use 17C10
Oops, realised my mistake haha
Post by: RuiAce on October 26, 2016, 07:49:05 pm
Oops, realised my mistake hahaNah all sweet. I think you could sort of tell what was going on because you were able to consider two or three being left handed, just that you thought in the wrong direction afterwards.
Post by: Nech on October 26, 2016, 07:52:00 pm
Post by: RuiAce on October 26, 2016, 07:53:47 pm
hey for q12c) the very last part, how does the cos() in the denominator turn into a tan()? i got stuck there but i knew it somehow had to = -1 for the lines to be perpendicular at that point
Post by: jakesilove on October 26, 2016, 07:53:48 pm
hey for q12c) the very last part, how does the cos() in the denominator turn into a tan()? i got stuck there but i knew it somehow had to = -1 for the lines to be perpendicular at that point
Because we know, from the question/graph, that cos(a)=tan(a). That's the whole point of the question! It took me a while to get that too :)
Post by: RuiAce on October 26, 2016, 07:55:31 pm
Because we know, from the question/graph, that cos(a)=tan(a). That's the whole point of the question! It took me a while to get that too :)Seems like last part of Q12 for both 3 and 4U were trippy. I stared at that for 2 minutes before I realised wait there must be a trick. And that's when I started thinking trig identities...
Post by: Nech on October 26, 2016, 07:57:08 pm
Because we know, from the question/graph, that cos(a)=tan(a). That's the whole point of the question! It took me a while to get that too :)
OMG lmao i spent a bit of time playing around with trig identities AHAHA, thanks :)
Post by: queueq on October 26, 2016, 08:06:32 pm
Do I get full marks??
Post by: sincetheend on October 26, 2016, 08:42:31 pm
Post by: RuiAce on October 26, 2016, 08:45:12 pm
Hey for the last question, finding values of t, I just used distance formula, then differentiated to find stationary points and confirmed with 2nd derivative that it was a min. I still got t= sqrt2 and -sqrt2Long and tedious approach for a 2 marker but no you would not be penalised.
Do I get full marks??
Post by: RuiAce on October 26, 2016, 08:50:19 pm
In regards to rawmarks.info, what does the data mean exactly? I'm interpreting it as the raw mark scaled to what's in the last column for them, is that right? It just seems to be very extreme, with an increase of 29 from 52 to 81 one year in Extension 1 Maths.It is extreme. Because fact is, courses such as Mathematics Extension 1 align MASSIVELY. The alignment is so high that it's almost unrealistic but it's not; it is most certainly legitimate.
A raw mark of ____ will align to a mark of ____ as reported on the raw marks database, for that year. The data is collected from people who have bought their raw marks and have chosen to submit it to the database.
Post by: sincetheend on October 26, 2016, 08:53:07 pm
Post by: Cindy2k16 on October 26, 2016, 09:34:09 pm
Considering how many times I got stumped during the exam I was pretty low on confidence by q14 too. The amount of marks I had to skip automatically puts me at ~80% or lower too (which was my aim...welp)
Probably the only things i could remotely feel alright about is that i got 10/10 on MC i think and i managed to get that weird y=tanx y=cosx perpendicular gradient question after only a short time of severe confusion lol
All in all it was a horrible experience for me haha..time to study for physics and chem now
Post by: Mei2016 on October 26, 2016, 09:43:03 pm
My thoughts on the test was... is it just me, or is the parametrics part of Q14 actually hard? (I mean, it is prelim work and I only managed part i) )
-I think I liked the MX2 test better because there was more time...
-I got the first two parts of the binomial q out, but when I tried adding the first two parts together... it just didn't work out...
-The second part to the circle geo was hard to see... (funny how I got the 4 mark circle geo in 4 unit and didn't see this one...)
-And I was just wondering if I'd get a mark taken off for writing in a domain restriction for Q11a) the inverse function... (the root sign bothered me in the test... should've just ignored it...[sigh])
Also, is it advisable to get E4 in MX1 and MX2 to consider doing uni maths? (like level 1141...)
Post by: Anonymouse1 on October 26, 2016, 10:18:26 pm
Post by: sincetheend on October 26, 2016, 10:32:36 pm
How much would around 75% raw scale for this test?
Probably 90+ based on this; http://rawmarks.info/wiki/Mathematics_Extension_1
So an E4.
Post by: RuiAce on October 26, 2016, 10:37:39 pm
It was.. a pretty awful exam for me.... I didn't deal with the tricky questions well and some of them took me a while to get and others I kept trying to do and didn't get them in the end and had to skip :/ Since some questions took me a little longer to figure out/I kept trying different things to figure out, I even ended up running out of time and couldnt do the last binomial part and the majority of the final locus question (uh though I doubt I would've been able to do it). I wasn't sure if the question was simple and if I spent a little longer on it I would get the answer ._.Tbh the bulk of the paper's difficulty WAS in its trickiness. On a broad scale it wasn't that bad but some subtleties were meh. Also a bit of time management i guess; never spend too long on the same question.
Considering how many times I got stumped during the exam I was pretty low on confidence by q14 too. The amount of marks I had to skip automatically puts me at ~80% or lower too (which was my aim...welp)
Probably the only things i could remotely feel alright about is that i got 10/10 on MC i think and i managed to get that weird y=tanx y=cosx perpendicular gradient question after only a short time of severe confusion lol
All in all it was a horrible experience for me haha..time to study for physics and chem now
It can be annoying though, being disappointed by the paper to the point that your motivation for Q14 drops a bit. Not much can be said there though unfortunately, that's for each and every person.
But yeah, definitely focus on the remaining exams now
Ok.... (post-test feeling: was horrible)A twist was there in the last part of the parametrics but I don't know about hard. Probably more peculiar than the norm but it only really required breaking it down. That being said that's important though; Q14 is usually about breaking things down and then building it all back up.
My thoughts on the test was... is it just me, or is the parametrics part of Q14 actually hard? (I mean, it is prelim work and I only managed part i) )
-I think I liked the MX2 test better because there was more time...
-I got the first two parts of the binomial q out, but when I tried adding the first two parts together... it just didn't work out...
-The second part to the circle geo was hard to see... (funny how I got the 4 mark circle geo in 4 unit and didn't see this one...)
-And I was just wondering if I'd get a mark taken off for writing in a domain restriction for Q11a) the inverse function... (the root sign bothered me in the test... should've just ignored it...[sigh])
Also, is it advisable to get E4 in MX1 and MX2 to consider doing uni maths? (like level 1141...)
MX1 is shorter (and the paper's smaller) mainly because there just isn't that much stuff in the course to cover.
Yeah, that was not an add. That was a subtract. The trick with binomial was, like said, to eliminate the 2n-1
A generous marker won't care, but yeah that was a cube root.
The preference for MATH1141 is to have a combined mark of at least 175 between MX1 and MX2. Which is roughly E4 in both but there's a bit of breathing room if you barely miss it. But these are recommendations - it's ultimately your own skill that matters.
How much would around 75% raw scale for this test?
I don't expect it to be that much different to 2015, but maybe a tiny bit better. See the raw marks database for the historical data but I only compare with a basis.
Post by: Anonymouse1 on October 26, 2016, 11:10:24 pm
And personally 2015 was my favourite paper, while doing it timed i got 93 with about 40 mins to spare.. The questions were direct, but this year they curved around the question alot and asked you to do like 10 things before getting to the actual core of the question. In my opinion, I felt like 2016 was one of the hardest papers.
Post by: edmododragon on October 27, 2016, 10:21:50 pm
Post by: RuiAce on October 27, 2016, 10:23:30 pm
I have to say, I didn't expect to have to use the reference sheet at all, but short cutting the equations of the tangents and normals in the last question was quite a timesaverI laughed when I realised that the formula sheet would actually come in handy for parametrics.