Math Ext 1 Predictions/Thoughts (1 Viewer)

tywebb

dangerman
Joined
Dec 7, 2003
Messages
1,712
Gender
Undisclosed
HSC
N/A
one eight seven's solutions: https://cdn.discordapp.com/attachme...90/Mathematics_Extension_1_2021_Solutions.pdf

So now we have an answer to 12a. Guess we'll have to wait for NESA to upload the question paper to find the rest of 12a (direction field on writing paper) - unless someone else uploads it before then - unlikely because answer booklets would have been collected.

EDIT: Seems like one eight seven's answer to 12a is wrong. The direction field with answer is here (thanks to andy!):

andi!.png

Also go back to post #268 for the original picture without solution.
 
Last edited:

notme123

Well-Known Member
Joined
Apr 14, 2020
Messages
1,002
Gender
Male
HSC
2021
one eight seven's solutions.

So now we have the answer to 12a. Guess we'll have to wait for NESA to upload the question paper to find the rest of 12a (direction field on writing paper) - unless someone else uploads it before then - unlikely because answer booklets would have been collected.
wait why does 12 a go like that, why doesnt it do upwards. that curve was super ambiguous

also for the concrete one i put units cubes, would i still get the mark.
so far ive gotten full aside from the concrete one, the diagram and the sample distribution one where i might lose a mark for the inequality
 
Last edited:

tywebb

dangerman
Joined
Dec 7, 2003
Messages
1,712
Gender
Undisclosed
HSC
N/A
wait why does 12 a go like that, why doesnt it do upwards. that curve was super ambiguous
Well it might.

Problem is 12a direction field was on the writing paper - and wasn't uploaded with the rest of the paper. Hence so far there is no way to check if one eight seven's solution to 12a is correct or not.

A similar problem arose in 13a in the Extension 2 paper - and we managed to successfully reconstruct it from memory of students who sat that paper.

I think reconstructing a direction field from memory would be a much more difficult task so maybe in this case it is better to wait for NESA's version.

EDIT: The direction field has since been put online. See above in post #282 for andy!'s answer and also #268 for the original.
 
Last edited:

Siwel

Active Member
Joined
Aug 21, 2021
Messages
208
Gender
Male
HSC
2021
wait why does 12 a go like that, why doesnt it do upwards. that curve was super ambiguous

also for the concrete one i put units cubes, would i still get the mark.
so far ive gotten full aside from the concrete one and the sample distribution one where i might lose a mark for the inequality
yeah i did a similar thing and went past an x=intercept then up
 

Siwel

Active Member
Joined
Aug 21, 2021
Messages
208
Gender
Male
HSC
2021
they better be lenient with this one because i can see a bunch of different answers being possible
ive heard that it cut off and went both ways, anyway said i got zero to try and better estimate the mark, as soon as the paper said put name on booklet 12 i knew instantly what was happening
 

notme123

Well-Known Member
Joined
Apr 14, 2020
Messages
1,002
Gender
Male
HSC
2021
ive heard that it cut off and went both ways, anyway said i got zero to try and better estimate the mark, as soon as the paper said put name on booklet 12 i knew instantly what was happening
mine was above the x axis the entire time and had a min at that area where it was nearly flat. why did nesa choose to spice it up this time, and what is the chance both 3 and 4u papers had an extra booklet
 

Siwel

Active Member
Joined
Aug 21, 2021
Messages
208
Gender
Male
HSC
2021
mine was above the x axis the entire time and had a min at that area where it was nearly flat. why did nesa choose to spice it up this time, and what is the chance both 3 and 4u papers had an extra booklet
chance was very high after the x2 had a booklet, honestly the amount of just mistakes made in that paper by me think my x2 raw mark percentage will be higher then x1
 

Jojofelyx

Well-Known Member
Joined
Jan 3, 2021
Messages
410
Gender
Female
HSC
1998
yeah i did a similar thing and went past an x=intercept then up
I just made a dot to dot for all the direction field things going through P. Kinda concerned because i thought it looked absolutely fine, but the solns given above look very different. Mine looked like this:
 

Attachments

Siwel

Active Member
Joined
Aug 21, 2021
Messages
208
Gender
Male
HSC
2021
I just made a dot to dot for all the direction field things going through P. Kinda concerned because i thought it looked absolutely fine, but the solns given above look very different. Mine looked like this:
well i did similar except mine went to a x-intercept after the y-intercept and then up but then again that was my first time drawing a solution to a direction field so probs wrong
 

Jojofelyx

Well-Known Member
Joined
Jan 3, 2021
Messages
410
Gender
Female
HSC
1998
chance was very high after the x2 had a booklet, honestly the amount of just mistakes made in that paper by me think my x2 raw mark percentage will be higher then x1
Haha same dude, coming out of that exam i think i nailed everything except the very last question, but after looking through the paper i realised that i just misread like so so so many questions. The volume one, bounds, area, literally got the right answer for q8 in the m/c but coloured in the wrong one 🥴 ah well rip :\
 

Jojofelyx

Well-Known Member
Joined
Jan 3, 2021
Messages
410
Gender
Female
HSC
1998
well i did similar except mine went to a x-intercept after the y-intercept and then up but then again that was my first time drawing a solution to a direction field so probs wrong
Yeah i dont recall exactly how i did it, i just remember not going nearly as far down as the one in those solns lol
 

notme123

Well-Known Member
Joined
Apr 14, 2020
Messages
1,002
Gender
Male
HSC
2021
I just made a dot to dot for all the direction field things going through P. Kinda concerned because i thought it looked absolutely fine, but the solns given above look very different. Mine looked like this:
i got exactly this too and so did my friends
 

Siwel

Active Member
Joined
Aug 21, 2021
Messages
208
Gender
Male
HSC
2021
Haha same dude, coming out of that exam i think i nailed everything except the very last question, but after looking through the paper i realised that i just misread like so so so many questions. The volume one, bounds, area, literally got the right answer for q8 in the m/c but coloured in the wrong one 🥴 ah well rip :\
the concrete volume is like a 1 for me, the projectile motion i accidentally made a t disappear meaning i couldnt do the ceiling bit, q14 literally looking at the solutions i had everything write but for some reason it never gave me the answer for some of them and q14a) misread thought wind was going south, never knew comprehension skills in maths were this poor :/
 

Siwel

Active Member
Joined
Aug 21, 2021
Messages
208
Gender
Male
HSC
2021
also where was the trig calc ik one multiple choice but really? I swear trig (not trig calc) is like in both yr 11 and 12 and a big part so how only like 5 marks
 

Jojofelyx

Well-Known Member
Joined
Jan 3, 2021
Messages
410
Gender
Female
HSC
1998
the concrete volume is like a 1 for me, the projectile motion i accidentally made a t disappear meaning i couldnt do the ceiling bit, q14 literally looking at the solutions i had everything write but for some reason it never gave me the answer for some of them and q14a) misread thought wind was going south, never knew comprehension skills in maths were this poor :/
Bruh, same fr fr. the very last question, i had everything pretty much set up correctly, and then just thought to myself "nah nup nope, you're not getting this". Same for the population of deer question, everything set up perfectly, just thought nah, had to just sub 1 number in to get the answer lol. Pretty sure the cohort of 130 or smthn in Ruse, are all getting 68+/70 lol
 

Siwel

Active Member
Joined
Aug 21, 2021
Messages
208
Gender
Male
HSC
2021
Bruh, same fr fr. the very last question, i had everything pretty much set up correctly, and then just thought to myself "nah nup nope, you're not getting this". Same for the population of deer question, everything set up perfectly, just thought nah, had to just sub 1 number in to get the answer lol. Pretty sure the cohort of 130 or smthn in Ruse, are all getting 68+/70 lol
the deer thing just annoyed me with how little space i had to write and the large numbers they picked
 

notme123

Well-Known Member
Joined
Apr 14, 2020
Messages
1,002
Gender
Male
HSC
2021
Pretty sure the cohort of 130 or smthn in Ruse, are all getting 68+/70 lol
what makes you say this. tbh the exam was kinda simple just the binomial one was very poorly worded, as with the standard one as well

just so happy the nesa gods answered our prayers and combinatorics was like 3 marks 🤩🤩🤩🤩🤩🤩
 

Siwel

Active Member
Joined
Aug 21, 2021
Messages
208
Gender
Male
HSC
2021
the 5theta/7 one was substantial.


for this one i had a really convoluted solution using auxillary and ended up with a nice sine thing then i realised shit its sine rule so ye
the sin theta thing was 4 marks all up, idk just expected more, there was no aux angle except multiple choice
 

notme123

Well-Known Member
Joined
Apr 14, 2020
Messages
1,002
Gender
Male
HSC
2021
the sin theta thing was 4 marks all up, idk just expected more, there was no aux angle except multiple choice
ye ik but i used auxillary for the plane one because i solved simultaneously using vectors instead of geometry and trigonometry
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top