i mean the 2022 and 2021 paper had unique questions, you probably can't find the harder questions in the past HSC papers or tutoring questions, they should atleast make the originality consistent
I mean of course they are connected to some well known results. But if you have seen the same type of question before you KNOW what result to apply, the difficulty with original 4u questions is the fact that you should have to think about how to approach the question (try various different approaches/results) rather than knowing it straight away.
I think you have a different interpretation of “original” to mine. Like, with your interpretation I could argue the reduction formula Q15a)ii) was “original” because that technique isn’t a standard thing you find in that context and it makes you think. But I doubt many people would call that question “original”.
If by “original” you really mean “unseen” then that is in the eye of the beholder as everyone has had different exposure levels to different types of questions. For example, someone who has never seen Cauchy Schwarz inequality or Taylor series expansion may think a question that covers it in the HSC is cool/unique but someone who has been exposed to that (e.g. through a private tutor) may think a question on that is boring/unoriginal.
Also, I doubt the exam writers would necessarily be expected to go out of their way to read every question lying around in obscure places, especially if they’re not easily/publicly available (e.g. a tutoring resource), just to make sure no one thought of the same idea they did.