Thank you, will definitely check out the website. Is it hard though? I have heard its crazy hard... Kinda scared lol
I wouldn't say it's hard - but it's certainly different, and it's different that causes most people to find it to be hard.
Let's be honest, here - since year 7, you've dabbled in algebra. You continued dabbling in year 8, 9 and even 10, and you honestly haven't made much leg-way. Then, you get to VCE, and for year 11 you take methods. Methods actually takes you somewhere with algebra, and so for a few people, methods is incredibly hard because they're not used to spending less than three years to cover a single concept.
Then, at the end of year 11, you might choose to do specialist in year 12. So, you take specialist - and all of a sudden, you deal with these weird things called "vectors". And "complex numbers". And you've never seen any of this before - but you might understand it, and might do well in it. However, a few of your friends are so confused by these new concepts (because they're not used to seeing things without dabbling in them for several years earlier) that they find specialist too hard to continue with, and so drop down to method.
Starting university maths is sort of like an in-between of the two - doing it as extension would be like starting specialist. You start off with linear algebra (ie vectors) - you've never really done anything with it before, and up until now you're used to having seen the basic concept over and over again before you start to move on. This time, you move on at the same pace that you've seen the basic concept. Thankfully, it would get easier with the second topic (functions of multiple variables) - you've dabbled in the basic concept before, but still the lecturers are going to set a pace, and you'll be expected to keep up.
So, it's not hard - you've just not seen it before, and its the unknown that people find scary.
(note: I did not do extension maths, I just have an idea of the material)