Yeah, I was actually doing ext 1 maths in prelim, dropped to 2 unit and then to General after doing poorly 1st term HSC due to a combination of personal stuff and lack of motivation/ slacking off.
Would you recommend actual bridging courses or just personal study? Thanks
Probably both. On top of that, ECON1001 Introductory Microeconomics actually had an additional lecture running for people needing some basic maths, so there's that (although I think at one point I saw a lecture recording of them going through quadratics...). But honestly, just focus on calculus.
If you have a 2U textbook that has content on differential and integral calculus (even better if it has applications of calculus), I recommend going through that, exercise by exercise. There's a lot of users on this forum who would gladly explain concepts to you or help you with questions. You could probably find notes/courses/guides/videos online on calculus. Just to be safe though, I do recommend the bridging course. (There is only a small component of calculus in first year, but the maths gets heavier every year, especially if you plan on entering the honours stream.)
I have no idea whether
this is good or not, but he has pretty decent reputation, and he only goes through the HSC stuff, which is enough. (Some videos on YouTube may be more geared towards uni students, and hence more formal and difficult to grasp.) Just remember: differential calculus is about
change (e.g. gradients), and integral calculus (for your intents and purposes) is about
quantity (e.g. area, volume). (Though you won't encounter integral calculus in first year economics, it's useful to learn it. Operationally, integration is the opposite of differentiation.)
Good luck!