Class of 2025 (2025 HSC CHAT) (22 Viewers)

Dzeeshr

New Member
Joined
Aug 8, 2025
Messages
5
Gender
Male
HSC
2026
had anyone figured the answer to the last question in the maths adv cssa? or did someone already did and i just couldn't be bothered to read the history of this discussion.
if I remember correctly we had y=x^2 and y=ln(x)+k. I just differentiated both functions and made them equal to one another and solved for x. Because the tangent at A is the same gradient for both curves. With the x co-ord you can sub back into x^2 and you have the (x,y) of point A and it all flows from there. can find k as such. the 2nd part with the integral was simple once you had k.
 

Scryne

New Member
Joined
Dec 24, 2023
Messages
25
Gender
Male
HSC
2025
You guys reckon I could still pull off a raw score of 70 in math standard assuming I averaged 50 in internals and got an 80 in the HSC?
 

qweeosh

Active Member
Joined
Feb 11, 2023
Messages
125
Gender
Female
HSC
2025
if I remember correctly we had y=x^2 and y=ln(x)+k. I just differentiated both functions and made them equal to one another and solved for x. Because the tangent at A is the same gradient for both curves. With the x co-ord you can sub back into x^2 and you have the (x,y) of point A and it all flows from there. can find k as such. the 2nd part with the integral was simple once you had k.
differentiation makes sense, I unfortunately didn't think of that. Thank you!
 

mickeyd_357

New Member
Joined
Jul 21, 2025
Messages
9
Gender
Female
HSC
2026
if I remember correctly we had y=x^2 and y=ln(x)+k. I just differentiated both functions and made them equal to one another and solved for x. Because the tangent at A is the same gradient for both curves. With the x co-ord you can sub back into x^2 and you have the (x,y) of point A and it all flows from there. can find k as such. the 2nd part with the integral was simple once you had k.
thats what I did as well
@Dzeeshr do you think you got anything wrong
 

ashleyashley

Well-Known Member
Joined
Mar 1, 2025
Messages
310
Location
Australia
Gender
Undisclosed
HSC
2025
if I remember correctly we had y=x^2 and y=ln(x)+k. I just differentiated both functions and made them equal to one another and solved for x. Because the tangent at A is the same gradient for both curves. With the x co-ord you can sub back into x^2 and you have the (x,y) of point A and it all flows from there. can find k as such. the 2nd part with the integral was simple once you had k.
i did that but i kept getting 0.47... instead of 0.04... 😭😭 i spent like 30mins staring at my page trying to figure out where i went wrong and i never found out why
oh well at least i got 2 or 3 marks for it
 

Kat.crazi

Well-Known Member
Joined
Aug 25, 2024
Messages
613
Gender
Female
HSC
2025
Our school gave replacement questions for stuff we hadn’t done and I found those harder than a lot of questions on the actual paper bruh
 

fluffy_unicorns

Active Member
Joined
Sep 12, 2024
Messages
91
Gender
Female
HSC
2025
I didn’t think of solving with the derivatives 😔 i still wrote the intergrals, but couldnt complete solving them ofc bc i didn’t have A or k. Hopefully i’ll still get a mark or two still tho
 

reniiiblaseee

Active Member
Joined
Mar 27, 2025
Messages
254
Gender
Female
HSC
2025
You guys reckon I could still pull off a raw score of 70 in math standard assuming I averaged 50 in internals and got an 80 in the HSC?
depends on ur rank, could either get u a 60 internal or 85 internal, all depending on how ur cohort performs
 

Users Who Are Viewing This Thread (Users: 0, Guests: 22)

Top