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April 19, 2024, 06:56:14 am

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aqsarana_

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #15 on: February 20, 2016, 03:51:20 pm »
0
Hi!
At the moment I'm doing HSC Trigonometry and I'm really confused about when to change the calculator's mode to Degrees or Radians. How can i be able to tell when to change the mode?
Thank You.

jamonwindeyer

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #16 on: February 20, 2016, 05:35:10 pm »
+3
Hi!
At the moment I'm doing HSC Trigonometry and I'm really confused about when to change the calculator's mode to Degrees or Radians. How can i be able to tell when to change the mode?
Thank You.

Hey aqsarana! Awesome question. Your calculator should be in radian measure by default, since you must use radians for trigonometric calculus. The only time you switch to Degree measure is if degrees are used in the question, that is, values are given in degrees. This normally happens with geometry questions. For these questions, switch to degree measure, then switch back immediately when you are finished.

But yes, by default, leave your calculator in Radian measure. Only switch to Degrees if you see degree measurements in the question.

Hope this helps  ;D

RuiAce

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #17 on: February 20, 2016, 05:44:51 pm »
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To make what Jamon said more explicit.

You will find that in questions that ask you to be in degrees, there will be a degree symbol (°) present. As soon as that goes missing, naturally assume radians.

Happy Physics Land

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #18 on: February 20, 2016, 05:48:51 pm »
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And by personal experience there will definitely be cases where you would forget to change from radian mode to degrees modes and this is gonna be very disastrous. So some of my friends decided to bring two calculators, one labelled degrees and another labelled radians. If you are struggling to remember to change to radian mode then you might like to consider that method.
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jamonwindeyer

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #19 on: February 20, 2016, 06:42:41 pm »
+2
And by personal experience there will definitely be cases where you would forget to change from radian mode to degrees modes and this is gonna be very disastrous. So some of my friends decided to bring two calculators, one labelled degrees and another labelled radians. If you are struggling to remember to change to radian mode then you might like to consider that method.

I also heard of students doing this! One person in my year did it, it's not a bad idea if you are so inclined!

jakesilove

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #20 on: February 21, 2016, 12:44:24 pm »
+1
Hi!
At the moment I'm doing HSC Trigonometry and I'm really confused about when to change the calculator's mode to Degrees or Radians. How can i be able to tell when to change the mode?
Thank You.

Definitely agree with all of the above: If the question mentions degrees, use degrees. If the question doesn't mention degrees, use Radians. Simple as that! If you sometimes get confused, maybe it is worth getting into the habit of highlighting every time you see a degrees symbol in a question, so you know you need to put your calculator into degrees mode.

Jake
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Phillorsm

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #21 on: February 21, 2016, 09:57:47 pm »
0
Hey jake, having trouble integrating this.
Integrate (4-(x-8)^2)^(1/2)
I know its a semicircle and the limits are 10 to 6, but I keep getting zero.
Is there a special way to integrate a semicircle and find the area? (Other than (pi*r^2)/2 )

Happy Physics Land

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #22 on: February 21, 2016, 10:01:45 pm »
0
Hey jake, having trouble integrating this.
Integrate (4-(x-8)^2)^(1/2)
I know its a semicircle and the limits are 10 to 6, but I keep getting zero.
Is there a special way to integrate a semicircle and find the area? (Other than (pi*r^2)/2 )

Hey Phillorsm:

Is your question a definite or indefinite integral?

Assuming that your question is an indefinite integral, the answer should not be zero because after all, area cannot be zero right? I like your approach of drawing a semi-circle and you have correctly identified the domain of the semi-circle. So all you really had to do was apply pi(r^2)/2 to find the area of the semi circle, and that will give you the integral (l believe you have identified that r=2 because 4 = 2^2). Considering that this is an indefinite integral question, you will need to add +C at the end.

(sorry just ignore the sintheta stuff in the background, they are irrelevant)



If you have any further questions dont hesitate to ask!

Best Regards
Happy Physics Land
« Last Edit: February 21, 2016, 10:13:20 pm by Happy Physics Land »
Mathematics: 96
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jakesilove

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #23 on: February 21, 2016, 10:07:51 pm »
+1
Hey jake, having trouble integrating this.
Integrate (4-(x-8)^2)^(1/2)
I know its a semicircle and the limits are 10 to 6, but I keep getting zero.
Is there a special way to integrate a semicircle and find the area? (Other than (pi*r^2)/2 )

Hey Phillorsm!

If you are looking to find the area underneath that curve, you've identified one great way to do it: by understanding that the graph is a semicircle, use the formula (pi*r^2)/2 !

However, you should also be able to integrate as normal and find the required result. I'm not at home at the moment, so can't write out a full solution, but hopefully someone else on the forums can!

Hope this helps! Let me know if there's anything you're unsure of.

Jake
« Last Edit: February 21, 2016, 10:37:13 pm by jakesilove »
ATAR: 99.80

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Loki98

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #24 on: February 23, 2016, 08:56:39 pm »
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Could someone please help with question 10a of the 2003 2u mathematics hsc paper :)

jakesilove

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #25 on: February 24, 2016, 12:09:02 am »
+1
Could someone please help with question 10a of the 2003 2u mathematics hsc paper :)

Hey Loki!

This is one of the more difficult Finance question I've seen. Once you learn the general method, however, you will have no problem! Below is my solution :)





Jake
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Phillorsm

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #26 on: February 26, 2016, 09:23:55 pm »
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Hey Jake, I just got my results back for my first 2u exam for year 12. It was on sequence and series, applications of calculus, integration and logs and exponentials. I got a 55/78 because I didn't finish the last section (logs and expos) of the exam. My teacher did say I smashed the first three parts though.
Firstly I wasn't super strong on logs and exponentials from the beginning, and secondly I spent way too long trying to work out a question earlier in the exam that i was sure I could get. It was a question where you had to find the equation of a parabola given its vertex and x intercepts.
Based on all this, how do you think I should move on. What can I learn from this experience, and just because I got a 70% on this exam, does that mean i'm doomed to around a 70 for the rest of my 2u math career? Like, this is the real thing now, is it still possible to recover?

Happy Physics Land

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #27 on: February 26, 2016, 10:15:25 pm »
+1
Hey Jake, I just got my results back for my first 2u exam for year 12. It was on sequence and series, applications of calculus, integration and logs and exponentials. I got a 55/78 because I didn't finish the last section (logs and expos) of the exam. My teacher did say I smashed the first three parts though.
Firstly I wasn't super strong on logs and exponentials from the beginning, and secondly I spent way too long trying to work out a question earlier in the exam that i was sure I could get. It was a question where you had to find the equation of a parabola given its vertex and x intercepts.
Based on all this, how do you think I should move on. What can I learn from this experience, and just because I got a 70% on this exam, does that mean i'm doomed to around a 70 for the rest of my 2u math career? Like, this is the real thing now, is it still possible to recover?

Hey Phillorsm:

Im clearly not Jake (obviously) but I just wanna to be here to tell you that getting around a 70 for your first 2u assessment is really nothing to worry about. Im not just saying this to boost you with blind confidence, Im saying this because it's too early a stage to give up. If you've ever been to one of Jake's lectures, he told us his experience not being able to finish TWO PAGES of his trial exam for maths ext 1 upon his return from the international science forum. Yet he still got a remarkable 98. So there is absolutely nothing for you to worry about.

Another real life example from me: one of my classmates for accelerated maths only got 60 percent in his first exam, and throughout the entire course his mark fluctuated around 70 percent. Yet in the end he scored a mark of 85 for his 2u mathematics. So if you look at yourself now, you are in a much better situation. You know majority of your stuff in the first three sections and you are in a better starting point than my friend! As a person who's gone through 2u hsc mathematics before, I can tell you that in the end, after the tonnes of practise papers you have done, you will begin to realise how much you have improved and how surprisingly better you will be end up doing in your hsc exam. So dont get defeated by this one exam, because to be honest, I have failed 2 of my first assessments this year as well and I found out that in the end, they only contribute to 5% (sometimes not even) of your final mark.

Ok hmmm regarding exam techniques, I think you might have been stuck on a question for too long and that may have caused your inefficiency in time management. Of course you will hear people saying to you "skip the question if its taking too long", but I do empathise with you because sometimes we are fairly certain we have seen the particular question before and it shouldnt take us much time to complete it. Unfortunately sometimes we can make a mistake that we wouldnt realise because its too trivial or the teacher could have added something extra in the question to make the question one step harder. As a general rule of thumb for me, if there is a time-consuming question that you know you definitely can solve in a multiple choice section, SKIP IT AND COME BACK LATER. Surely, if we solve the question it boosts our ego, but its not worth spending 5 minutes on a question that merely awards you with 1 mark. If a question is in the free-response section and you have looked at it for 3 minutes not knowing where you should be starting, then I would also suggest to skip it and come back later.

Logarithmic function and exponentials definitely can be hard, perhaps one of the hardest concepts in 2u. I would recommend, ofc, to do past trial papers (you can find links in atarnotes to access trial papers) and practise those questions on the topic. Also practise some past HSC questions.

Tips I would give on logarithmic functions:
- (This is especially common with difficult integration questions involving logs). KNOW YOUR YEAR 8 GEOMETRY WELL! If you look up question 16b) on 2015 paper you will realise that you have to draw a rectangle and use integration about y-axis to figure out the area encompassed by the y-axis, the scope of the rectangle and the curve first, then use your area of rectangle to subtract that area to find the area you were asked to find. This is a VERY USEFUL TECHNIQUE.
- I often struggled with the idea of changing the bases, simply because its not frequently tested. But if the teacher wants to make a hard question, you would need to change the base as a technique to approach your final answer, so be familiar with the process
- I remember in one of my earlier exams, I was asked to find the area under a log curve and I accidentally wrote 1/x as an integral of ln x. Sometimes when the exam pressure kicks in, you really can be making those sorts of mistakes. So just remember that at your level, you definitely wouldnt be required to integrate ln x, and if you did end up having to integrate ln x, you know there must be an easier way.
- There is also that kind of typical question that's involved in both integration and the integration of logarithmic functions that involve several parts. The first part would most likely ask you to differentiate and then in the second step ask you to integrate. Keep in mind if you see this sort of question in integration/integration of logs and exponentials, you know that you can use part I in part II. You can somehow manipulate what you are required to integrate in part II into the outcome of differentiation in part I and then just integrate it saying "using part I, we know that _____ is a primitive function to _____, hence the integral is ______"

I will say this much for now, but yes definitely do not give up. The game has just started and sometimes its good to be on a lower end of a ladder because it avoids arrogance and it allows you to put in more effort to do better in the next exams.

Good luck!

Best Regards
Happy Physics Land
Mathematics: 96
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English Advanced: 92
Physics: 95
Chemistry: 92
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2017 ATAR: 99.70
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jakesilove

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #28 on: February 26, 2016, 11:15:57 pm »
+2
Hey Jake, I just got my results back for my first 2u exam for year 12. It was on sequence and series, applications of calculus, integration and logs and exponentials. I got a 55/78 because I didn't finish the last section (logs and expos) of the exam. My teacher did say I smashed the first three parts though.
Firstly I wasn't super strong on logs and exponentials from the beginning, and secondly I spent way too long trying to work out a question earlier in the exam that i was sure I could get. It was a question where you had to find the equation of a parabola given its vertex and x intercepts.
Based on all this, how do you think I should move on. What can I learn from this experience, and just because I got a 70% on this exam, does that mean i'm doomed to around a 70 for the rest of my 2u math career? Like, this is the real thing now, is it still possible to recover?

Hi Phillorsm!

Firstly, I just wanted to congratulate you on your fantastic 2u result! 71% is nothing to be worried about: in fact, I would say that the fact that you were able to do so well in the sections you completed puts you in good stead for the  HSC (more on that later).

Next, I want to echo the words of HPL. I absolutely agree with his advice, and won't repeat anything he has said. Specifically, the idea of skipping questions and coming back and knowing specific techniques to answer difficult questions.

The only point that I would add, when discussing ways to speed up exam completion, is DO PAST PAPERS! Do them again, and again, and again. This is the best way to speed up answering questions. The reason is that, if you can spend one minute less per question figuring out what you actually need to do (ie. by recognizing that an answer should be identical to a practice response you did the day before), you will gain so much extra time. This is extremely valuable in finishing assessment tasks!

So, my main tip for you is to just do hundreds of past papers, in timed conditions, again and again. There are never too many papers you can complete!

The fact that you know your stuff is a really good indicator of how you are going in the year. Timing can always be improved, and the more past papers you do the faster you will get in completing individual questions. Knowing the content in-depth, however, is a far more difficult task. So, congratulations for where you are at! Just keep doing past papers, and keep in mind the comments made by HPL.

Jake :)

 
ATAR: 99.80

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Studying a combined Advanced Science/Law degree at UNSW

amandali

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Re: 96 in 2U Maths: Ask me Anything!
« Reply #29 on: February 27, 2016, 08:10:47 am »
0
cos(2x+pie/6)=1/root2     -pie<=x<=pie

how do i find the angles in a simple way without getting the angles confused?