# Search results

1. ### Questions about the sample paper on vectors from ACEHSC.net

Hi all, I am having a hard time trying to understand the wording of the following questions. First of all, for part b), I am really confused by what it means by "in the opposite direction of z perpendicular to z". We're talking about only one vector here so how can one vector both in the...
2. ### Mechanics - Resisted Motion - Getting stuck on the last part (part iv) -Please help!

Hi there, I am so close to getting over this question but unfortunately I am still getting stuck on the last part. I have tried to a lot of ways but none has worked out. Attached below are the question, the answer to part iv) along with my full working out for the previous parts respectively...
3. ### I am self-learning mechanics (projectile motion). How do I solve the question below?

Hi all, I have just learnt the basic of 4u mechanics and I feel quite overwhelmed by the number of formulae I have to remember for this topic. I also don't know which formulae I should use. I am getting stuck on the question below, I got up to the expression linking t and alpha but since I don't...
4. ### "Describe the motion..." mechanics question

Oh I understood it now. Thanks for the help!!!
5. ### "Describe the motion..." mechanics question

Hi all, I am a bit confused by the last part of the following question. I wonder whether the velocity will ever each 0 or not. The thing is v=cos^2(x) which means when x=pi/2 v=0. However, the expression for x in terms of t is x=tan^-1(t) which means that each will never reach pi/2? If that is...
6. ### COVID-19 and school closures

Hi all, hope you have all been well. I wonder if school is still optional next term? What I mean by optional is you don't have to go to school unless you don't have anyone at home to supervise you, exactly like what we are doing at the end of this term. Are they going to keep classes online for...
7. ### IB Maths Tutor - Sydney

Not only is Drongoski an excellent tutor but he is also a very kind and accomodating person. He has a profound knowledge of Mathematics, especially topics like Vectors and Simple Harmonics which are often considered as the most difficult areas in the 4u syllabus. His approach to integration is...
8. ### How do you know when to use u-substitution for integration and what u is? (example included)

Thank you for your reply. Could you please share with us some of your tips for integration? You seem to be an expert in this area.

10. ### How do you know when to use u-substitution for integration and what u is? (example included)

Thank you so much for your reply! Thank you for the insight!
11. ### How do you know when to use u-substitution for integration and what u is? (example included)

Hi, the title pretty much speaks for itself. There are so many methods to use in 4u integration so how do you identify when to use u-substitution and what the value of u is? I came across the following question (part c) in which it already hints at using u-substitution and gives you the suitable...
12. ### (Vector) How to express a vector in terms of another vector?

For question 15c), I am not quite sure what to do to express those vectors in terms of the other vectors. I have never come across any similar questions nor have I ever learnt any formula applicable to this. Could someome please explain to me the concept behind it and give me a hint to solve...
13. ### HSC Marks Thread 2019

Hi, I'm not really sure whether this following email address is the most apt one or not but I have contacted UNSW via this address before for info about a course that I was interested in and it seemed that the guy knew his stuff well. info@unsw.edu.au. All the best!
14. ### HSC Marks Thread 2019

Congratulations on your 94.7 ATAR. That's amazing! It just occurred to me that if you're an international student, the cut off for you might be different from that for domestic students (usually 5 marks lower). For example, I'm pretty sure atar cut off for med for international students is like...
15. ### Tips on how to excel in Integration

So I’m half way through 4u integration and I just feel so overwhelmed by all the rules, different types and methods to solve it. At the same time, I also feel like I really like doing integration (no idea if this makes sense :)) ) as it is just so interesting and satisfying when you get it...
16. ### Do they allow you to use “reversing the step” in the HSC? (Nature of proof)

Hi, thanks for your interest in my thread. Does that mean that in the HSC it is simply not enough just to write “reverse the steps to get the proof”?
17. ### Do they allow you to use “reversing the step” in the HSC? (Nature of proof)

so in the hsc, simply writing “reverse the steps to get the proof” is not enough? Does it mean that I need to re-write the whole thing? If so, it’s gonna be really time consuming. I reckon I’ll use contradiction as you told. Thank you so much for your reply
18. ### Do they allow you to use “reversing the step” in the HSC? (Nature of proof)

Allow me to elaborate on the title. So the new syllabus has introduced a new topic called “nature of proof” which basically consists of proving problems. At tutor, I was told that according to NESA, you are not allowed to assume something is true and work backwards to the end. However, at school...
19. ### ATAR Prediction (based off prelim results) + Help with Subject Concerns

Wow. It’s so inspiring to know that not all BOS Maths beasts are prodigies. Could you please further elaborate on how you self-study 4u Maths? Thank you so much in advance
20. ### Thoughts on maths 3u/4u textbook

Highly second this. I have purchased this and can conform that the questions are very interesting. The only downside is that it contains some typo errors since it’s new and the author hasn’t published solution for year 12 3u yet.