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Mathematics for the Adventurous Self-Learner

neilwithdata.com

191–200 of 216 posts

Re: Mathematics for the Adventurous Self-Learner

#191

Do any of you all have some tips for understanding mathematical notation? I feel this is often poorly explained, and it feels like a language all its own that just does not speak to me. I did pretty well in calculus, but I still don't really understand what the dx was supposed to represent and in reality I was just really good at pattern matching when it wasn't supposed to be there anymore. I try to read papers now a…

3blue1brown channel on calculus:

https://www.youtube.com/watch?v=WUvTyaaNkzM&list=PLZHQObOWTQ...

Re: Mathematics for the Adventurous Self-Learner

#192
post #93

Earlier quoted context omitted.

I found that the community on brilliant.org can be quite toxic. I was a member for awhile, but quit due to the people on the site.

I’m using brilliant, but just the courses, not any of the community parts. What was the failure mode?

I think the final thing was on the daily challenges; I always tried to solve them before looking at the answers even If I don't know the "proper" math to do so. I had posted my (correct) solution that I got to by writing a program to work it out; and I got some replies saying I was an idiot for not doing in the proper (math) way.

Re: Mathematics for the Adventurous Self-Learner

#193
post #116

There is 3 books listed that essentially cover the freshman (first year) courses in Calculus. And 4 for Linear Algebra. If you work your way through even 2 different books for one topic, you are going to have a broader foundation in the topic than a normal math student in a normal university after completing the corresponding course. And you will have spent much more time, too. University courses don't usually cover…

To be clear, I don't at all advocate that people work through all the Calculus books. Likewise for the Linear Algebra books. My aim was to provide alternative options (which are easier, cheaper, etc.)

Re: Mathematics for the Adventurous Self-Learner

#194

Earlier quoted context omitted.

Precalculus in a Nutshell is a beautiful little book by George F Simmons, which pretty much captures everything you need to know to undertake the study of calculus. https://www.maa.org/press/maa-reviews/precalculus-mathematic... Linear algebra is quite a beautiful, approachable subject; and a certain amount of it is necessary to make the leap from single variable to multi-variable calculus. Without a good grip on cal…

Simmons? WOW! He's a serious mathematician, e.g., as in his George F. Simmons, Introduction to Topology and Modern Analysis . I studied it one summer in an NSF program at Vanderbilt. Then I concluded that he is one heck of a good math writer.

He has elementary textbooks on calculus and differential equations, as well, so you get an entire development from precalculus all the way to topology and analysis from the coherent viewpoint of a legit (but sympathetic) mathematician.

Re: Mathematics for the Adventurous Self-Learner

#195

Earlier quoted context omitted.

>As someone who has done a PhD, done research in math, done research in computing, worked in research and development in industry, taught math Me too so now what? I don't think your credentials give you any real authority but just make you look like you're gatekeeping. >Doing the exercises is playing with the objects to try to answer specific questions. Great so then we're in agreement: playing with the object is doi…

> I don't think your credentials give you any real authority ... It wasn't intended to, it was to provide a context for my opinion. So let me state my opinion as clearly as I can, and then I'll leave it. * Math is a "contact sport" ... you have to engage with it; * Reading books is not, of itself, engaging with the math; * Watching math videos is not, of itself, engaging with the math; * Well designed exercises are a…

See? It's pretty hard. This is what I've been dealing with for the last 20 years of on and off trying to get through the bigger Rudin book and a couple others.

Just reading doesn't get much at all. Not even a superficial overview. I tried it. It's essentially a meaningless combination of words after a certain point.

Reading extremely thoroughly is actually marginally useful. Stopping to think, do all these assumptions matter, why, what if one of them changes, etc, pencil in hand, making notes, testing things out. I've managed to "understand" the topics when doing this, and so far it's been the highest ROI method. But it does still leave one feeling like something is missing. Just because you can sight read music doesn't mean you're an expert on the piano.

Doing exercises is a huge jump on investment, and the return on that investment is a bit questionable from my experience. A couple reasons: first you don't know if you did them right. If you did them wrong then that's negative ROI. Second you don't know what a "reasonable" workload is. It varies by author. Is it three problems per chapter, is it all of them, are some orders of magnitude more difficult than others? Without some guidance it's hard to know if your difficulties are due to not understanding basic material, or due to that problem being a challenge geared toward Putnam medalists. So they may cause you to question your understanding and thus mentally roadblock you unnecessarily. And finally with proofs (and this may be a me thing), it's pretty easy to say "I guess this is okay(?)" and move on, even if you're not sure. Since nobody is ever going to review it, and it's just a homework problem, it's very very hard to will oneself to make sure every assumption is correct and you're not missing anything, even if you feel like there's a good chance you are. Or perhaps I just don't have the constitution to do so.

So while I think doing exercises is necessary for a deeper understanding, I don't know whether the ROI is worth it outside of a classroom perspective. You need feedback for exercises to be beneficial. At least, I feel like I do.

Finally, is even taking a class that useful if the end state is that two years from then you'll have forgotten most of it and so what was the point. Can you claim knowledge of a subject that you've never actually used beyond some homework problems and exam questions, or is this still a superficial understanding? Having an ends where that knowledge gets used seems critical.

I feel like I have some knowledge but I don't feel like I'm there yet. But I don't know if I know where there is. Maybe that's the biggest challenge. Does completing a Ph.D. even get you to there? No idea. But, I guess it's up to the individual to decide what they want out of it. Nobody can determine that for you.

Re: Mathematics for the Adventurous Self-Learner

#196

Earlier quoted context omitted.

What is an example where you missed mathematical knowledge to do your job? Honestly curious, I never needed any math during programming for my job.

Yeah, I always think I "should" brush back up on my now-rusted-solid math skills—I doubt I could pass the final for any math class I took past maybe 9th grade without studying, let alone anything I took in college—but they've rusted for a reason. I never fucking use them. If I do it's some narrow little thing that I look up, do, then never look at again. [EDIT] and then there's "what is math?". The memorization from…

> [EDIT] and then there's "what is math?"

Good remark. I wouldn't call arithmetic math, nor would I call using a Boolean expression math. I am currently working on a compiler bug that has to do with liveness analysis. That is an algorithm, which kind of is math, but the actual bug is just 'oh, for some reason the registers that the function arguments are passed in are not marked as live', and I wouldn't say that I had to use any math.

In my job, I'm usually either fixing bugs, parsing formats, making different API's work together by converting stuff or writing wrappers around API's. I wouldn't call any of this 'math', and if you'd ask me I have never used math at work (which is a shame really, because I really love math).

Re: Mathematics for the Adventurous Self-Learner

#197
post #98
post #6

I know this is going to be the case for likely nobody, but I have browsed most of the self-study math threads that pop up here as a forever-on-my-todo-list thing and I have a remark to make: I have yet to find a guide that does not start with the assumption that you graduated highschool. That is a very reasonable assumption to make. We are in a community of technology and engineering, it would be a bit ridiculous to…

I solved this by just buying all the high school math textbooks and going through those on my own. I preferred this way, because it lets you have the same background as everyone else. In attempt #1 I was jumping ahead to read the interesting stuff (calculus), and while I could make some progress, it was needlessly difficult because I didn't start from the basics. It attempt #2 I started from the very beginning (cours…

While I'm not sure there actually are a lot of high school prerequisites for higher maths, I think the experience of attempts 1-3 reflect pretty much what might be the key to studying maths successfully.

So in my first year of studying maths, I had 8 hours of maths lectures (and 4 hours of a minor which was of negligible effort). The exercises that came with the maths lectures made this a full-time program (and I estimate that while I didn't usually study all weekend, I typically only had 1-2 weekends per year in which I didn't look at anything at all). So one thing that can easily go wrong is underestimating that for every minute spent reading / listening to a class, one would want to spend 4 minutes working the problems.

The other comment I would have is that, yes, university level mathematics is (at least it was for me) incredibly hard. The reward is also astonishing: All these hard exercises I struggled with one year, are easy to do on a napkin during breakfast in the next year.

Re: Mathematics for the Adventurous Self-Learner

#198
post #181

Does anybody have any experience with How to Prove It? by Velleman? Recently I was thinking of starting on it, but I'm not sure about the level of commitment necessary.

I worked through this book to learn how to do proofs. It turned out way more fun than I expected. The book really did demystify proofs for me. It took several months of studying - there are many exercises. But completely worth it. I'm glad I have read this book before studying Group theory and Real analysis.

Thanks!

Re: Mathematics for the Adventurous Self-Learner

#200
post #165

Earlier quoted context omitted.

Might want to ask current students about those classes first. My experience with community college math developmental classes was: "Go to this AV room, watch these videos, do these workbooks. If you have questions, I have office hours on these days.". Which was terrible. I did have someone I could come to with things I didn't understand, but it was obviously not something they liked doing and you had little choice ab…

Holy crap! I wonder if it's a rural vs. metro area thing. Our CC was definitely classroom work- again, decades ago.

Same. Was a normal college thing. Classroom, teacher, chalkboard, occasional glazed eyes... but also the expectation you'll ask questions, and the ability to get feedback or clarification.
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