Andrew's IB Maths Vault

Henlo kiddos! Really hope everyone's doing great. Tis is the time of the year when N23s have barely started the course (and I see many of them are doing sequences and series) while M22s better start revising for the exams. Just a friendly reminder: unless you've been told explicitly  by your school that exams won't go forward, please  do yourself a favour and study NOW if you wanna do well. Due to popular demand (~40 votes in the Mocks server, not a small proportion) one of my focuses for this year is writing end-of-topic revision guides. I probably won't write these for EVERY SINGLE TOPIC , as some topics never  show up as a grade 7 question (I'm looking at you, correlation).  For more info re: the structure and the purpose of this booklet, read the second page, but here's a tl;dr: Different target audience - this booklet is aimed at everyone, including those shooting for a 7. Some questions are deliberately  set at that level. For more accessible questions, pl...

Hello hello hello! As you know we'll talk about trig equations after trig functions.  After a short hiatus due to me unable to comprehend thermo, I'm now temporarily  back with an ENTIRE (yes, entire) module on trig equations. Have fun with it. Answers included at the end. Link: Where are we going, where have we been? In our journey on trigonometry so far, we started with Pythagorean theorem and right-angled trigonometry. Extending our definition to larger angles, we develop the sine and cosine rules for non-right triangles and then to the entire unit circle.  The "point on the circle" model gives rise to our trigonometric functions, namely, sine and cosine functions. We did a bunch of transformations to fit our function with our data, which is then used to predict future values. The question arises: is there a way we could solve some  equations without using a calculator? Answer: special trig values. More details on that soon. Why are we interested in special trig v...

Hey y'all. For the last few days, I've seen some students struggling with conditional probability on the IB server. This isn't news or anything; conditional probabilities are usually poorly done overall, especially the SL folks. This post summarises what commonly show up on examiners' reports and how you can avoid it. The concept of probability in IB is ENORMOUS, so I'll just focus on basic probability and combined probability. A solid foundation in this would ensure a good shot at solving the more complex, massive-tree-diagram-wordy-thingy questions. Basics of probability (1) giving answers which were greater than 1 You've probably heard of this statement 283187 times, but it's surprising the number of students who "innocently" report a probability of 2.0 due to a calculation error when dealing with decimals. Honestly. If y'all ever  report a probability greater than 1, I'd leave the room and SCREAM because you didn't pay attention to ...

Hey y'all! Due to not-so-popular demand I'm back with two series of tests for AISL and AIHL. I admit I've ignored the AI folks for a while, and this is my futile attempt to make up for it. c: AIHL Statistics and intro to prob: AIHL Statistics and intro to prob ANSWERS: AISL Statistics and intro to prob: AISL Statistics and intro to prob ANSWERS: AIHL Probability distributions: AIHL Probability distributions ANSWERS: AISL Probability distributions: AISL Probability distributions ANSWERS: Stay safe y'all. If you hate online school or just life  in general, remember that everything will be alright. Love, Andrew Credits:  AdventurousAndrew#7499

Here it is, the last part of this module. It is the summary of everything we've done so far, from identifying features to sketching devilish functions. And no way is better than ending this module with MORE questions that y'all can have a go at. Disclaimer, as usual: the questions are inspired by the books I've got my hands on, so it's normal if you find some questions similar to your textbook. The next module on trigonometric equations should be posted soon. I'm still in the process of writing the answers to the questions argh . It's gonna be a good ride. Thanks for tuning in with what I've posted over the last two weeks! Credits: AdventurousAndrew#7499

Thi s part of the module is on reciprocal and inverse trig functions, reserved for AAHL students only. From my experience, the IB doesn't ask tricky questions related to reciprocal and inverse trig, considering we haven't covered a lot of trig identities at this stage of the booklet. Consider this some downtime before the big game of trigonometric equations. Preview of next section:  End-of-Module Review and a practice quiz. Credits: AdventurousAndrew#7499

First post in 2022! Hey there. If you're looking for more trig functions torture fun, hang on tight. Today we'll put the properties of trig functions into solving more realistic problems. Surprisingly these questions are generally very poorly  done, simply because Kids cannot map the relative height on the wheel with the height of the trig functions Kids cannot interpret the properties of trig functions properly because the wordings are bad Kids' understanding of functions is weak, leading to their inability to recognise what  to do and what to substitute where and 7749 other reasons. Here's my two cents that might help y'all to avoid the common misconceptions, especially the second bullet point. You should be very  solid at properties of trig functions before reading on. Credits:  AdventurousAndrew#7499