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# Spriteling

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1. ## Manipulating double angle formula...

Irene: sin(pi/2) = 1, so your answer doesn't work. You'd have to do sin(x) = 0 at pi. Therefore, when 6x = pi, sin(6x) = 0. Therefore, x = pi/6.
2. ## Manipulating double angle formula...

Well, the first tip is, always look at what the question wants you to do. They say that they want the answer in the form a sin 6x, where a is an integer. Therefore, you would have to use the form sin2x = 2sinxcosx. Now, when you look at 30 sinxcosx, you see that it is already in that form, because it can be written as 15 (2sin3xcos3x). Therefore, the 3x has to be half of the original angle, so that would be 6x. Therefore, it reduces down to 15 sin6x, which is the form that they want. Thus, you see that a = 15. The fact that everything is a multiple of 3 doesn't really matter in this problem. The double angle formula is always sin2x = 2sinxcosx. The angle 2x could be anything. If x = 3x, in this case, then 2x is 6x. If it was 16x, then 2x would be 32 x. In that cause, the double angle formula for sin32x would be 2sin16xcos16. I hope that all made sense.
3. ## Study Breaks

We got the week before exams as a study break. It used to be two weeks, but we were really behind in the syllabus for a lot of subjects, so it got reduced to one week.
4. ## The Physics Specimen Paper

Section A just has a set number of points. (25, I think.) They can divide that up into as many questions as they want.
5. ## Name Your IB School

International School of Indiana, USA, May 2009! Less than a month to go!
6. ## [MATH HL] Continuous probability question

In a continuous probability function, the probability of something happening is the area under the curve. Thus, you would integrate to find the probability. Therefore, you cannot have something like (P=0) for a continuous probability function, because you can't have area under the curve for just one point. Therefore, you should that by trying to integrate between 0 and 0, and showing that you get an answer of 0.
7. ## General May 2009 Exam Discussion - Preparation ONLY - No exam paper discussion

I feel fairly well prepared for maths, physics, and chemistry. Less for for English A1 and History. French ab initio is just a joke.
8. ## What countries did your IAs get sent to? (For moderation)

My EE went to Vietnam, my TOK essay went to Thailand, my physics IA went to Canada, my chemistry IA went to...Africa, I think, and my maths portfolios went to Portugal. I basically went everywhere!
9. ## Physics Options

I though relativity was a fairly easy option, but so was astrophysics. <shrug> To each his own, I guess.
10. ## Physics Options

You're fine. You can do any two options you want on the actual exam, even if you didn't study them in class. The school doesn't register you for options for physics, like they do in maths, so they can't penalise you. I think a fair few people change right before the exams because their option was poorly taught in class. So, don't worry.
11. ## University Offers 2009

Predicted grades Maths, physics, and chemistry HL: 7 English SL: History SL and French ab initio: 6 TOK and EE: 3 Total: 43 Other qualifications (standardized test scores etc.) SAT I: 2200 UK University of Edinburgh - Conditional for 2nd year entry - 32 overall with 6,5,5 in HLs University of St Andrews - Conditional for 2nd year entry - 36 overall, with 6 in maths and physics University of Leeds - Conditional - 36 overall with 6 in maths and physics Imperial College London - Conditional - 40 overall, with 7 in maths and physics, 6 in chemistry, and 5 in English SL University of Cambridge - Rejected Other countries: USA: RPI - Accepted. Comments With any luck, I'll be attending the University of Edinburgh next year.
12. ## IB test!?!

If you can, get your maths teacher to make review packets for you of past IB questions on certain topics. I did this for HL maths and it helped immensely. This way, you can practise IB style questions and get the hang of them while reviewing topics. After you've done that, I'd move on to past papers, and time yourself, so you are sure you can do them in the allotted time.
13. ## How to approach revision?

Well, what I've been doing is reading my history textbook and writing outlines from scratch about major topics I know will be covered in paper 2. For example, I wrote a huge outline on Stalin's rise, consolidation of power, and rule. It really helped because I read the book, and I wrote it down, so I was studying in two ways. The outlines are really time consuming, though (3-4 hours each) and I'm not sure how much time you have to revise.
14. ## Group 4 subjects as an EE ? advice ?

Do something you love. If that's chemistry or biology, do your EE in one of those subjects. Otherwise you'll get bored, and you won't do as well. Also, make sure your EE is experimental, because EEs in the sciences that are experimental always score better than theoretical EEs.
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