CSSA trial (advanced/ extension maths) (2 Viewers)

carrotsss

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CSSA's answer to their 2023 Adv paper Q28b is wrong. They should have checked ln(16/9)-1 is negative and so the distance is ln(9/16)+1 (or written as ln(9/16) - -1 as question said to write it as ln(a/b)-c)

Checking doesn't seem to be CSSA's strong point because in the CSSA solutions for their 2023 Ext.2 paper Q16c there are actually 2 answers 219.1m/s OR 223.5m/s. They arise from the equation
View attachment 39610
In CSSA's solution the absolute value blissfully disappears and then they only get 1 answer 219.1m/s.

I was not so careless and put my solutions here for comparison and you will see how I got the 2 solutions: https://4unitmaths.com/cssa2023e2-tywebb.pdf
cssa seem to have a tendency of giving dodgy solutions, they have lots of problems in chemistry and physics as well
 

Luukas

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It is not impossible. Here are my solutions ...
May I ask why you put expenses as 200 + 20n in Q23? Doesn't that make the expenses in the first week 220? The question says that they start at 200 and then increase by 20 per week.
 

Luukas

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If you were taught properly you would not feel so bad about it.
This comment is very similar to what I hear the teacher who led the writing team has been saying to his class - and that he feels sorry for students who have teachers complaining that the exam was too difficult...
 

bruhmoment.

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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.
 

WeiWeiMan

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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

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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.

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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

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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
 

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