• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

CSSA trial (advanced/ extension maths) (1 Viewer)

tywebb

dangerman
Joined
Dec 7, 2003
Messages
2,202
Gender
Undisclosed
HSC
N/A
I also put up my solutions to the Ext. 2 CSSA 2023 at https://4unitmaths.com/cssa2023e2-tywebb.pdf

I used an out-of syllabus method for question 12aii choosing 3 planes out of 6 to find the point of intersection of the 2 lines using a matrix equation. This turned it into a question about the intersection of 3 planes having the same point of intersection as the 2 lines.
There are 2 versions of the 2023 ext. 2 cssa, one with Q11d uncorrected and the other has it corrected. If you happen to get the uncorrected cssa, I should point out that there is an error in the original paper.

The one I used was the corrected version Q11d:
2023cssa-q11corrected.png
You will see "at rest" is crossed out.

Obviously if it is at rest at the origin it would not have that equation.
 
Last edited:

bruhmoment.

Active Member
Joined
Jun 19, 2023
Messages
244
Gender
Male
HSC
2024
i did solutions to 2024 ext 1 and 2 cssa



many of my methods differ from cssa solution methods often leading to more efficient soutions
yo just wanted to ask, how did u figure out how to do q10 of the 3u cssa 2024 exam. I've literally not heard a SINGLE person that hasn't guessed it. everyone just 50/50 it for b/c since answers were so similar. also with 13d, im probably wrong and so are others from my school but everyone ended up getting 36/25pi. forgot what the question is (something related to hemispherical bath). Thanks.
 

tywebb

dangerman
Joined
Dec 7, 2003
Messages
2,202
Gender
Undisclosed
HSC
N/A
Although most of my solutions for advanced are shorter than cssa's I nevertheless sometimes went the other way - for example I spent half a page showing working for the MC and cssa didn't bother with the working for MC. They did in ext 1 and ext 2, but not for advanced.

I think if solutions don't just assist marking but also will be used in the future for revision, then it is better to show working
 

tywebb

dangerman
Joined
Dec 7, 2003
Messages
2,202
Gender
Undisclosed
HSC
N/A
anyway here is another version of solutions this time in video format and it is for all the cssa maths in 2024: https://sites.google.com/parra.catholic.edu.au/2024-cssa-mathematics-trial-so/home

but i looked at the ext. 1 12c video and he said something ridiculous. He said the question said fired from the wall in part ii but meant fired from tower.

well dude it didn’t say fired from tower it said fired from wall!

my solutions are consistent with what the question actually said not what they meant to say but didn’t. so i’m still not changing mine.
 
Last edited:

tywebb

dangerman
Joined
Dec 7, 2003
Messages
2,202
Gender
Undisclosed
HSC
N/A
Last edited:

WeiWeiMan

Well-Known Member
Joined
Aug 7, 2023
Messages
1,026
Location
behind you
Gender
Male
HSC
2026
yo just wanted to ask, how did u figure out how to do q10 of the 3u cssa 2024 exam. I've literally not heard a SINGLE person that hasn't guessed it. everyone just 50/50 it for b/c since answers were so similar. also with 13d, im probably wrong and so are others from my school but everyone ended up getting 36/25pi. forgot what the question is (something related to hemispherical bath). Thanks.
the vectors visualising for mcq10 is legit useless 💀
you're basically figuring out the number of ways you can arrange m right moves and n up moves

this is basically just arranging m R's and n U's in a straight line
this can be done 2 ways:
first way: (m+n)!/m!n!, where (m+n) is the total number of letters and n! and m! account for the double ups

second way: choose m R's from m+n U's and R's, so m+n C m = (m+n)!/m!n!

hence C
 

Average Boreduser

Rising Renewal
Joined
Jun 28, 2022
Messages
3,207
Location
Somewhere
Gender
Female
HSC
2026
lowkey gotta love when you pull nearly all of 14 and lose majority of your marks in the q11 🤦‍♀️ I shouldve 95ed this shit if I just stayed focused and used my time wisely. Word of advice to students doing 3u accelerated, remember to balance all your subjects out. If you continually do maths, it will take a toll on your processing speed+ awareness when you are doing exams. Coming from someone who did exactly that in this test and got hit w a 82 🤦‍♀️
 

bruhmoment.

Active Member
Joined
Jun 19, 2023
Messages
244
Gender
Male
HSC
2024
lowkey gotta love when you pull nearly all of 14 and lose majority of your marks in the q11 🤦‍♀️ I shouldve 95ed this shit if I just stayed focused and used my time wisely. Word of advice to students doing 3u accelerated, remember to balance all your subjects out. If you continually do maths, it will take a toll on your processing speed+ awareness when you are doing exams. Coming from someone who did exactly that in this test and got hit w a 82 🤦‍♀️
82 still aint that bad bro😭. i got bummed with a 70. legit aced q14 (somehow got 3/5 for cycloid question) and everything else was fine and did silly mistakes in q13 like ffs.
 

Average Boreduser

Rising Renewal
Joined
Jun 28, 2022
Messages
3,207
Location
Somewhere
Gender
Female
HSC
2026
82 still aint that bad bro😭. i got bummed with a 70. legit aced q14 (somehow got 3/5 for cycloid question) and everything else was fine and did silly mistakes in q13 like ffs.
bruh how did u get 3lmfao. I got 3.5 and I pulled out the 2sin^2(x/2) wtf
 

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

Top