• 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

Maths ext 2 trial (1 Viewer)

peepeepoopooo

New Member
Joined
Jul 30, 2024
Messages
14
Gender
Male
HSC
2024
Completed the CSSA Maths ext 2 trial on Monday was curious of what other people thought of it, I found most of the q)16 very challenging except for the cos integration
 

xoNat

don't worry, be happy
Joined
Apr 30, 2022
Messages
1,454
Gender
Undisclosed
HSC
2024
Completed the CSSA Maths ext 2 trial on Monday was curious of what other people thought of it, I found most of the q)16 very challenging except for the cos integration
I found it really challenging
Walked up to this girl in my class after and we just started laughing
 

tywebb

dangerman
Joined
Dec 7, 2003
Messages
2,206
Gender
Undisclosed
HSC
N/A
Well I thought they could have found a better way to find the minimum distance between skew lines.
Here is my alternative solution to 15ciii which is much more efficient than the method in the paper, and also doesn't rely on any previous parts either.
15ciii-alternative.png
 

tywebb

dangerman
Joined
Dec 7, 2003
Messages
2,206
Gender
Undisclosed
HSC
N/A
Hey how about 16a. The official solutions are very long. You can do it in 1 line like this:

16a.png
 

tywebb

dangerman
Joined
Dec 7, 2003
Messages
2,206
Gender
Undisclosed
HSC
N/A
Here is another shorter way, but less algebraic, more of a combinatorial approach.

if you have m girls and n boys, you can line them up in m!n! ways such that all girls come before all boys, and in (m+n)! ways without that restriction.

Hence m!n!<(m+n)!
 

Average Boreduser

Rising Renewal
Joined
Jun 28, 2022
Messages
3,209
Location
Somewhere
Gender
Female
HSC
2026
They took 8 pages to get up to 12b. I did all that in 1 page. Here are the rest of my solutions, many of which are quite different to the official ones


Haven't checked for typos though. I'll do that tomorrow.
wait so why did u use hyperbolic trig for 7.? Wouldn't that require you to prove its properties to actually use it? Wouldn't it be easier to use in syllabus mthods? I was just wondering since theres already complexity in there being hyperbolic trig, but now theres also a complex number inside the function so like surely this wouldn't suffice in a real exam?
 

tywebb

dangerman
Joined
Dec 7, 2003
Messages
2,206
Gender
Undisclosed
HSC
N/A
wait so why did u use hyperbolic trig for 7.? Wouldn't that require you to prove its properties to actually use it? Wouldn't it be easier to use in syllabus mthods? I was just wondering since theres already complexity in there being hyperbolic trig, but now theres also a complex number inside the function so like surely this wouldn't suffice in a real exam?
makes it quicker

cosh(ix)=cos(x)
 

tywebb

dangerman
Joined
Dec 7, 2003
Messages
2,206
Gender
Undisclosed
HSC
N/A
also you know it is going to be much easier if the i is in the cosh than if it isn’t

think about it

what is going to happen if the i is in the cosh? imaginary parts cancel and it simplifies

what is going to happen if the i isn’t in the cosh? nothing! so nothing cancels.
 

tywebb

dangerman
Joined
Dec 7, 2003
Messages
2,206
Gender
Undisclosed
HSC
N/A
Last edited:

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

Top