[HN Gopher] Ask HN: I suck at math, where to start?
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       Ask HN: I suck at math, where to start?
        
       As a self taught programmer I feel like I have a big gap on my math
       knowledge, where can I start learning math concepts that will help
       me in my career?
        
       Author : novakor
       Score  : 150 points
       Date   : 2022-01-12 12:42 UTC (10 hours ago)
        
       | sesm wrote:
       | Try 'Mathematics can be fun' by Perelman.
       | 
       | I was a 'math prodigy' in school. To me mathematics was always
       | about solving problems, learning any theory/apparatus makes much
       | more sense when you understand what problems it helps you solve.
       | As a programmer you probably have a problem-solution mindset too.
       | If you just have fun solving problems and slowly build your
       | mathematical foundation from there, you'll probably discover that
       | you don't suck at all, just the way you were taught mathematics
       | at school was too dogmatic.
        
       | progre wrote:
       | Are you sure you suck at math? I used to think I sucked at math
       | (now I think I'm merly bad at it). Turns out I suck at _numbers_.
       | I can 't get a feel for them. Manipulating equations and such
       | though I found quite easy back when all that was fresh in school.
       | 
       | As for career advise, depends on what you want to do: There is
       | not much use in learning calculus if you end up in astatistics-
       | heavy field like data science. I'd say figure out what kind of
       | computing you want to work with and see if there is a specific
       | part of math that are useful there, if there even is one.
       | 
       | I've done work for finance and never had to go much deeper than
       | simple multiplication.
        
         | kasey_junk wrote:
         | I thought I sucked at math for a long time, reinforced because
         | my math teachers in school believed it too.
         | 
         | Turns out I suck at spatial thinking. I can't manipulate things
         | like plots and curves in my head and they don't help me
         | understand mathematical principles. Algebra and logic though
         | come easy to me. So learning math became an exercise in
         | translation.
         | 
         | That is to say, please don't think you suck at math and
         | definitely look at different ways to learn the same concepts if
         | something is not clicking.
        
         | lief79 wrote:
         | Agreed, I've used trig once since I left college for an image
         | manipulation problem. Discrete mathematics, Algebra,
         | statistics, and depending on the roles ... linear algebra are
         | far more likely to be useful.
        
       | k3liutZu wrote:
       | I strongly suggest Khan Academy --
       | https://www.khanacademy.org/math
       | 
       | Sal Khan is a great teacher
       | 
       | ---
       | 
       | I am doing now a uni course (economy/informatics) and had to
       | brush up on calculus and other math areas. Khan Academy helped me
       | understand a lot of required concepts.
        
       | jcadam wrote:
       | I managed to get through a BSCS w/ a minor in mathematics. And 20
       | years later I still count on my fingers when working out
       | problems. Or counting change. Or working out the final price on a
       | 30% off sale while shopping.
       | 
       | The odd look I got from from calc professors while taking exams
       | was kinda funny.
        
       | orionblastar wrote:
       | http://khanacademy.org
        
       | bennysomething wrote:
       | This is a big coincidence for me, a few hours ago I posted a
       | reply to someone else saying I've decided this year to plough
       | through khan academy at least until I can do some calculus.
       | 
       | I'm in the same boat as you I think.
       | 
       | I'm 40, work as a programmer and I have a fear of being found out
       | for not know enough maths.
       | 
       | I bought "math for programmers"
       | https://www.manning.com/books/math-for-programmers But I realised
       | I really need to get better at algebra first.
       | 
       | I'm treating this as how I treated learning the guitar on my own
       | when I was 12, sit in my room at night and practice.
       | 
       | I'd be interested to hear what people think of my khan academy
       | plan :)
        
       | [deleted]
        
       | tatsean wrote:
       | https://www.khanacademy.org/
        
       | BFay wrote:
       | I really like Jeremy Kun's writing: https://jeremykun.com/ and
       | recommend his book, A Programmer's Introduction to Mathematics:
       | https://pimbook.org/.
       | 
       | So far I've only read the first few chapters of the book, and the
       | exercises often feel too difficult to me. But I think he does a
       | great job of easing into mathematical notation, pausing to
       | reflect on what a seasoned mathematician might be thinking when
       | they come across that notation. He also makes a lot of analogies
       | to programming, and has example programs that are easy to follow.
       | It's helpful to have that angle to understand things from.
        
       | silent_cal wrote:
       | I find it helpful to start with "quantitative reasoning" instead
       | of "math" if you're not math person... Math people speak "math
       | language" which can be frustrating if you're not cut from that
       | cloth.
       | 
       | Here's an example of a good quantitative reasoning textbook that
       | I looked at once, it is pretty well received by non-math people:
       | https://www.amazon.com/Using-Understanding-Mathematics-Quant...
        
       | schleck8 wrote:
       | If you happen to be german speaking
       | 
       | Maths for high school: https://studyflix.de/mathematik-schueler
       | 
       | Maths for university: https://studyflix.de/mathematik
        
       | gspr wrote:
       | Do you struggle with mathematical reasoning in itself, or with
       | different aspects of mathematics (aspects that are built on, and
       | work based on, said reasoning)?
        
       | [deleted]
        
       | xtiansimon wrote:
       | Same situation. It actually helped me to read about the history
       | of math. I found a love for some ideas in math and dispelled some
       | myths I had about the "Queen of the Sciences".
        
       | mixedmath wrote:
       | If you have a math-savvy person in your circles, it might be a
       | good idea to set up a chat with them. I think a good beginning
       | point would be to identify a specific problem or concept that
       | you've encountered that gave you some difficulty, and then talk
       | it through with them.
       | 
       | In my experience as a mathematician, it is not always easy to
       | identify the source of frustration in a problem. Having a
       | different perspective can be really helpful. (Also in my
       | experience as a math educator, a shockingly large proportion of
       | problems stem from fractions, exponentials, and logarithms --- or
       | not knowing what a function is.)
        
       | warrenm wrote:
       | Check out this Farnam Street post -
       | https://fs.blog/mathematicians-lament-2
        
         | sjg007 wrote:
         | I agree with this. I think that the way we teach math is a
         | disservice to the kids. When you watch a talented
         | mathematician's lecture you always see how relatable and
         | intrinsically motivating it is.
         | 
         | On the flip side, I think that when people write about math in
         | scientific reports for example, they don't explain the math
         | they use either.
        
       | dboreham wrote:
       | https://www.youtube.com/c/3blue1brown
        
         | yboris wrote:
         | I second this recommendation. It's a lovely way to explore some
         | of the beauty of mathematics.
         | 
         | I have a BA in math and I think the most-useful mathematics for
         | everyone is _probability_ (math theory and basic calculations).
         | This is because you 'll be better able to deal with (quantify)
         | uncertainty. The concept to aim for is (learn enough so you can
         | understand and use) _expected value calculations_ - which are,
         | I think, the foundation of rational decision making under
         | uncertainty.
        
         | godwhoa wrote:
         | +1 I really enjoyed the "Essence of ..." playlists from
         | 2blue1brown.
        
           | [deleted]
        
       | sillysaurusx wrote:
       | > where can I start learning math concepts that will help me in
       | my career?
       | 
       | I wouldn't worry about it. The amount of math that a working
       | programmer needs is minuscule.
        
         | bigbillheck wrote:
         | Depends on the job.
        
       | ur-whale wrote:
       | IMO "I suck at subject X ..." simply means the amount of
       | work/time you're going to need to invest to master subject X is
       | larger (sometimes much larger) than folks who have a knack for
       | it.
       | 
       | It rarely means you're completely incapable of mastering subject
       | X.
       | 
       | The real question is: is the investment worth it? If it takes you
       | 5 years to master basic linear algebra because your brain truly
       | isn't wired for it, how much is the 5 years you are going to
       | spend going to pay back in the long run?
       | 
       | Oh, and: actually enjoying doing X is usually a _tremendous_ help
       | towards mastering it.
        
       | ianai wrote:
       | Time. Be honest about how much time you're willing to invest into
       | understanding math. You can understand math if you're willing to
       | give it the time, but without that time you're likely setup for
       | frustration.
       | 
       | Where to start?
       | 
       | Math is huge. I suspect discrete math may be the most useful to a
       | programmer who's looking to just be a more theoretical
       | programmer. Proof by induction stands out as a core, helpful
       | concept too.
       | 
       | Otherwise I suspect it's about problem domain. Geometry has its
       | uses as does algebra. It all kinda branches from there.
        
       | saityi wrote:
       | _Introduction to Graph Theory_ - Richard J. Trudeau
       | 
       |  _A History of Pi_ - Petr Beckmann
       | 
       |  _Journey through Genius: The Great Theorems of Mathematics_ -
       | William Dunham
       | 
       |  _How to Bake Pi_ - Eugenia Chang
       | 
       | These are all sort of 'pop-math' books -- that is, they're more
       | intended to spark a joy & love for math than teach rigorous
       | mathematics. _Great Theorems_ and _A History of Pi_ include a lot
       | of history (edit to add: in addition to covering the math
       | involved!) -- did you know some mathematicians in history would
       | duel over their theorems? That theorems were a carefully guarded
       | secret instead of something you shared?
       | 
       |  _Introduction to Graph Theory_ is specifically intended as an
       | introduction to mathematics for  'the mathematically
       | traumatized'.
       | 
       | In my opinion, after reading these, if you've sparked a joy for
       | the puzzles and fun of mathematics, then I would then suggest
       | branching out into more formal presentations of them relevant to
       | your interests... it's much easier to slog through a book on
       | abstract mathematics when you receive from enjoyment from the
       | puzzles presented.
        
       | ultra_nick wrote:
       | There's nothing better for filling math gaps than going through
       | Kahnacademy.
       | 
       | Start skimming at the 1st grade level and then slow down and
       | focus when you reach material that isn't easy.
        
       | motohagiography wrote:
       | Out of curiosity, what does it look like to not-suck at math?
       | 
       | Do you wake up in the morning and are reminded of constants and
       | theorems in everyday things and laugh empathetically with donuts
       | as you recognize your shared absurd topological homology, or go
       | to the office and automatically recognize what's possible and not
       | from its implied complexity class in office conversations? Are
       | you checking Bayesian priors in your interpretation of the news
       | or other risk?
       | 
       | This is only half kidding, as I also identify as useless at math,
       | but I think its words and concepts can be very funny, and I
       | wondered what someone who actually knew this stuff might think
       | about. It begs the question of what one is actually doing when
       | they are doing math as well. Are you reasoning with abstract and
       | quantitative models, are you writing papers and proofs of new
       | ideas, or are you encoding a narrative dynamic into a
       | symbolically defined logical relationship? Maybe you're just
       | being recognized as a peer by the community of people who
       | recognize each other as good at it?
       | 
       | When I learned music again later in life, I found I appreciated
       | the same things, but with better intuition and words for
       | articulating and reproducing them. Working musicians have a trade
       | where it's expected they can show up and perform in a group based
       | on sight reading of the notation, same as a programmer.
       | 
       | All this is to say, I see a lot of these "I can't math / how do I
       | math" threads and am always interested in them, but maybe we
       | should start with, "how does anyone math" first. So, how do you
       | math?
        
         | jscholes wrote:
         | > Out of curiosity, what does it look like to not-suck at math?
         | 
         | To me, it looks like the rest of your comment, wherein you
         | casually mention constants, theorems, topological homology and
         | other concepts that don't even come to mind for many people who
         | self-identify as being bad at maths (as I do).
        
           | motohagiography wrote:
           | Thank you, but I am mathematically illiterate. I can't
           | identify greek letters after sigma without looking them up, I
           | ignore equations in papers and other texts unless they are
           | supporting something that offends me, I don't have a working
           | understanding of why certain operations are meaningful or
           | their uses other than knowing there is probably a python
           | library that does anything I could need.
           | 
           | However, things have shapes and relationships, most of which
           | we can't physically see, but we can reason about and compare
           | them, and that's about as deep as I get. e.g. do things at a
           | certain level of abstraction have a similar shape, and what
           | are the words that describe that? Does this tell us more
           | about the thing itself, or the limits of our ability to
           | percieve it, and it's just an artifact of our lens? It's like
           | having an ear for music, where you hear fragments of other
           | pieces in everything, and interpret forms and symmetries and
           | respond to intuitions, expectations, and resolutions - but
           | not being able to play it.
           | 
           | I think we're entering into an era where we can finally have
           | punk math, where some idiots get on stage and the people
           | watching them go, "omg, this is terrible but fun, and I could
           | do this better," and a thousand bands get launched. When I
           | write stuff like that, it's because I don't mind acting as
           | one of those idiots. I figure if most of my favourite bands
           | can't read music, there's interesting math to be done by
           | people who aren't proving anything or making progress, but
           | intentionally or not, like all idiots, they exist as an
           | example to inspire others. :)
        
         | paulpauper wrote:
         | Knowing how to solve problems in a mathematically precise way,
         | such as writing down the formula for the expected value of a
         | path-dependent investing strategy an hour after conceptualizing
         | it. Like being a handyman but the formulas are your tools.
        
         | dleslie wrote:
         | I'm no mathematics savant, but math has always been easy for
         | me. I never recall struggling to understand concepts, even
         | through my university degree.
         | 
         | What I vividly recall is my fascination with algebra and
         | geometry as a child. While on hikes I would imagine the
         | equations necessary to approximate the flora around me, to
         | calculate the parts of the rays of light, and so forth.
         | 
         | And while I never applied myself strongly to homework, I did
         | pay with math as I've would pay an instrument.
         | 
         | That is to say, this should sound like how musicians describe
         | hearing the music of nature, and their fascination with sounds
         | and musical theory.
         | 
         | Math is an instrument that one can play to make beautiful
         | music.
        
         | ur-whale wrote:
         | > Out of curiosity, what does it look like to not-suck at math?
         | 
         | The speed at which you an understand, internalize and can put
         | to use a new concept when it is presented to you.
         | 
         | This is usually combined with the practice of the trade
         | providing you with actual pleasure, which is, of course, a
         | self-reinforcing loop.
         | 
         | Some folks can take a single semester of linear algebra and
         | absorb the majority of the thing, including learning far more
         | than the course required because they truly liked it.
         | 
         | Others can take the first half of their career to finally
         | understand the ideas and apply them properly.
        
       | javajosh wrote:
       | A related question: which part of math can be used to model
       | object-oriented programming? AFAIK set theory deals purely with
       | associations of objects, not how you make new ones. HS algebra is
       | concerned with simplifying and inverting numeric equations.
       | Meanwhile abstract algebra (and number theory) is concerned with
       | finding talking about broad categories of numbers, relating those
       | categories to each other, and making new, presumably interesting
       | (read: surprising) statements about categories of numbers. Math
       | is a study in "going meta" since each component of each activity
       | gets a name, which are further grouped and named into other
       | categories, limited only by what the thinker can stomach/finds
       | useful.
       | 
       | But I am hard-pressed to think of any mathematical construct that
       | reflects, even a little, the reality of OOP. This is evidence
       | that OOP is an engineering concern, not a math concern. That is,
       | OOP is one method to help humans deal with the complexity of a
       | large amount of shared, mutable state (SMS), by partitioning it
       | into smaller units of SMS. But math itself doesn't care about the
       | scale of anything, and will happily encode any state into a
       | single, very large integer, if you let it.
       | 
       | Some parts of programming are better grounded in math, like
       | functional programming and relational algebra. Some distributed
       | programming problems have some nice, ad hoc mathy treatment (e.g.
       | Paxos), but don't really have a clear correspondence to anything.
       | 
       | Interesting the field that is closest to programming in real
       | life, IMHO, is statistical thermodynamics. This is usually taught
       | as part of the physics curriculum, and is pretty math intensive,
       | and the field's remarkable job is to generally model microscopic
       | behavior and then predict macroscopic behavior of huge
       | aggregates. Programs always deal with huge numbers of tiny
       | things, each having unique degrees of freedom, (alternatively,
       | which have unique constraints), so there is some connection
       | there. ST is also the field most closely related to certain
       | "quant" jobs in the finance field, AFAIK, since the same tools
       | let you model individuals in an economy and from that predict
       | markets.
        
       | GuB-42 wrote:
       | What kind of math can help a programmer in their career?
       | 
       | There are some fields that can make use of math, like computer
       | graphics, machine learning and data science. Most of it being
       | linear algebra. But although they interest me, I don't work in
       | these fields. For actual, paid, work, I don't remember using math
       | beyond middle school level (ex: solving linear equations), and
       | even that is uncommon.
       | 
       | If you want to learn some math, maybe try playing with shaders
       | (see: https://www.shadertoy.com/ ) or more generally, 3D
       | graphics. There is lots of math in here, but that's awesome
       | looking math, and you can actually see the results.
        
       | josefrichter wrote:
       | It also helps not to tell yourself "I suck at math", that's a
       | very common self-fulfilling prophecy.
        
         | the_only_law wrote:
         | I am beginning to think "I suck at math" less and more of "I'll
         | never be good at it", from the comments on this thread.
         | 
         | I absolutely despise grinding and drilling uncontexualized and
         | contrived problems and have never been able to maintain
         | something stuff like that for very long. Which of course
         | becomes problematic at I find myself interested in problems
         | that require a decent grasp on some math.
        
           | Jtsummers wrote:
           | The grinding is, by analogy, equivalent to the "reader" books
           | in many languages. "See Spot. See Spot run. Run Spot, run!"
           | level and then up. It's very hard (for most people) to jump
           | from "I now know the English alphabet" to "I can read any
           | article in a literary magazine." Many people forget that they
           | went through that process because they did it so young, but
           | also because language (written and spoken) is far more
           | pervasive than mathematics. This pervasiveness means that you
           | have less "grinding" to do, because you get to learn just by
           | being in the environment the language is used in (if it's
           | your native language, or if you can afford or are otherwise
           | forced to move into an environment where it's the local
           | native language).
           | 
           | Unless you're like me as a kid, you don't look around and
           | start counting, adding, and multiplying based on the objects
           | or scenes that you see, and "thinking in numbers". Thus the
           | need for grinding, you need some math fluency (which takes
           | practice to develop and maintain, like any other domain)
           | before you can move on to more advanced topics (at least
           | easily). If you lack fluency, even at a low level, then you
           | have to do a refresher every time you try and get to
           | something moderately advanced. Which is frustrating, at
           | least, if not demotivating to the point of causing most
           | people to stop. The more fluent you are, the easier it is to
           | pick up an arbitrary advanced topic (at least to read, if not
           | to apply or extend).
        
         | ianai wrote:
         | Agree! I've seen many a mathematics professor struggle with
         | math. It's not innate to any of us. But certain of us have
         | spent more time with it and seen more of it. The time and
         | familiarity eventually goes a long way - to a phd, even.
        
         | ur-whale wrote:
         | > It also helps not to tell yourself "I suck at math", that's a
         | very common self-fulfilling prophecy.
         | 
         | Wholeheartedly agree, and this applies much more broadly than
         | math.
         | 
         | Once you've built the mental fence, breaking it down is a giant
         | PITA.
        
         | qsmi wrote:
         | Definitely.
         | 
         | I think when people say they suck at math what they mean is; I
         | find math homework extremely boring and unrewarding. Which
         | perpetuates sucking at math and only compounds. Then things get
         | worse as modern society works better for the individual when
         | one does not totally suck a math.
         | 
         | Kinda like, I suck at piano because I find practicing the piano
         | boring and unrewarding, but without the ramifications of
         | sucking at math.
        
         | kypro wrote:
         | Agreed, although it's good to recognise what your strengths and
         | weaknesses are. I would argue it's often better to focus on
         | being great at the things you're good at than trying to be
         | decent at stuff you really struggle with. If OP struggles with
         | math they may be better off focusing on something else, at
         | least if they're optimising for career success. If you're
         | optimising for happiness and enjoy math problems then ability
         | doesn't really matter.
        
           | qsmi wrote:
           | I suppose depending on how extreme we're going with
           | unfocusing on math.
           | 
           | But one doesn't really get to ignore math in life because of
           | money. You'll still need to figure some things out. I can say
           | I'm a poor painter so I'm just going to ignore that and
           | things will be fine. The cost of ignoring math can be quite
           | high.
        
       | upofadown wrote:
       | Chances are you actually suck at algebra. I went through this
       | issue when I started electrical engineering as part of an overly
       | elaborate midlife crisis. I got the book in the bookstore that
       | was supposed to bring you up to high school level and just did
       | all of the exercises. Then I did a whole lot of exercises for the
       | introductory university math courses.
       | 
       | Basically it is something you have to grind at. Once you do
       | enough problems all algebra will seem easy and you are done.
       | 
       | I am not sure that you actually _need_ math for programming. Code
       | is its own algebra.
        
         | Tutanota1 wrote:
         | This is so true. I sucked at arithmetic but was quite good at
         | Higher secondary maths.
        
         | amelius wrote:
         | > I went through this issue when I started electrical
         | engineering as part of an overly elaborate midlife crisis.
         | 
         | Did it ease your midlife crisis? Would you do it again?
        
           | sho_hn wrote:
           | As someone with a "Watch Later" queue recently filled up with
           | oscilloscope and variable power bench PSU reviews - I'd also
           | love to know.
        
         | randmeerkat wrote:
         | I'm curious, was getting the EE degree as part of a midlife
         | crisis worth it? Or would you have done things differently
         | looking back?
        
         | bigbillheck wrote:
         | I used to teach college calculus, and can confirm: if you're
         | not comfortable with algebra, you're going to have a bad time
         | of it.
        
         | ransom1538 wrote:
         | IF!! You have kids learning math is _right there_ with a full
         | program. I forgot all my math so I keep up with my kids and
         | help at least 15 minutes per day. I have been tripped up with
         | 5th grade word problems - it is fun. Follow along with your
         | kids math - it will move quicker than you think.
         | 
         | I remember my last math class: Number theory. I got through the
         | final, shook the professors hand and told him, "this is the end
         | of intellectual ability". I have never seen a professor laugh
         | that hard. Once you get past abstract math classes thin out
         | fast and it just gets weird.
        
         | dls2016 wrote:
         | I second the grind. There's not really a shortcut... like
         | lifting weights or practicing scales/rudiments.
         | 
         | I returned to grad school at 27 for math and had trouble
         | passing qualifying exams. I ended up using spaced-repetition to
         | memorize large sections of books and old questions. I had
         | previously shunned memorization... but coupled with focused
         | practice it is a powerful tool. Memorizing forces you to
         | distill the material and patterns to their essence and allows
         | you to recognize the patterns in new situations.
        
           | HumanReadable wrote:
           | I agree there are no shortcuts, but just like the scales will
           | come much more easily to someone naturally gifted at music,
           | so will algebraic operations to someone gifted at math.
           | 
           | We can all improve our abilities, but those not gifted has a
           | much steeper hill to climb.
        
           | 300bps wrote:
           | _There 's not really a shortcut... like lifting weights_
           | 
           | And just like lifting weights, you will lose it when you stop
           | doing it.
           | 
           | I remember doing the CFA program which is math and formula
           | heavy. I had hundreds of formulas memorized. I couldn't tell
           | you the formula to calculate the standard deviation of a
           | portfolio of three assets now if my life depended on it.
        
             | solaxun wrote:
             | This is my main qualm with testing as a means of validating
             | understanding. If you truly understand a topic, you will
             | probably pass a test on it. However passing a test most
             | definitely does not guarantee understanding.
             | 
             | I remember very, very little from the CFA exams (passed L3
             | about 10 yrs ago), because it tested surface level
             | knowledge of an incredibly broad array of subjects. Far too
             | broad to allow a deep-dive in any one thing. At the time, I
             | could fit a bunch of formulas in my head and regurgitate
             | them on command, but it was like filling up a leaky bucket.
             | I had to load that sucker up and run into the exam center
             | before it poured out.
             | 
             | IMO testing well is it's own skill, and has little to do
             | with understanding a topic. Understanding is when you've
             | forgotten all the stuff you've memorized, but you can work
             | your way back to a solution from first principles. I think
             | the only way to get to that point is genuine interest and
             | sustained study.
        
           | Py-o7 wrote:
           | I am a big fan of the working out analogy. In all cases you
           | need to have a decent plan then execute-- basically this
           | means showing up and putting in the work. If you do it right
           | it should be a bit painful at times.
           | 
           | And just like working out some people will progress more
           | rapidly than you and have an easier time at it. So what? As
           | long as your goal isn't to 'place' at the elite level, this
           | is irrelevant. You really just need to show up and embrace
           | the struggle. (For elite level tasks including grad school,
           | its a bit more involved.)
        
         | commandlinefan wrote:
         | > I did a whole lot of exercises
         | 
         | Same happened to me. I completed a BS in CS and learned just
         | enough algebra, trig & calculus to pass the classes and then
         | forgot almost everything. Many years after graduation, I came
         | across an interesting post in comp.lang.java - somebody was
         | asking how to create a java applet that could draw a 3D block
         | arrow that could orient itself in any direction. I'm pretty
         | sure somebody was asking for help with his homework, but I
         | thought it was an interesting problem so I started looking at
         | it and the first issue I ran into was drawing a line
         | perpendicular to another. I vaguely remembered that there was a
         | formula for computing the slope of a line perpendicular to
         | another and when I looked it up - in context to a problem I was
         | trying to solve - it just kind of "clicked" and I found it
         | interesting. From there I fell down the rabbit hole of re-
         | learning everything up to differential equations that I was
         | _supposed_ to be learning when I was an undergraduate.
        
         | jordanpg wrote:
         | Agree with this and would also add: in addition to being able
         | to do algebra fast and have it be second-nature, at higher
         | levels it helps if you are able to do it 100% accurately. 5
         | nines isn't enough.
         | 
         | I didn't appreciate this until I was a graduate physics student
         | and was frequently frustrated by minor algebra errors in long,
         | complex problems.
        
           | sdenton4 wrote:
           | What's important isn't being able to do it right quickly the
           | first time. It's having a strong habit of checking your work
           | as you go, both at a low level and a high level. (Kinda like
           | unit testing and integration testing...)
           | 
           | Fast arithmetic and algebra are fairly particular skills. As
           | one progresses into new world of math, the calculations and
           | operations may be completely different from what's been
           | practiced, making the fast math less useful. But a good habit
           | for careful progress is completely general!
        
           | bigbillheck wrote:
           | I've known a lot of mathematicians, some of whom were really
           | good, and five nines (one-in-one hundred thousand) is an
           | implausibly high standard for humans to reach. I'm certainly
           | nowhere near there.
           | 
           | What's worked for me is to develop an intuition about how
           | things 'should' look, so that if I do make a mistake I'll get
           | a 'hey, that's not right' feeling a couple steps later.
        
             | qsmi wrote:
             | Just to expand on this, when I worked as a grader in
             | college I noted on engineering test keys the professor's
             | answers were always roughly three short lines of
             | handwritten equation. But the student's answer section were
             | often totally darken with pencil they wrote so much. The
             | heuristic was definitely the longer the answer the more
             | wrong it was.
             | 
             | This is something I've taken to heart professionally too.
             | If the equations are getting out of hand it's either wrong
             | or I need some simplifying assumptions (like that cow needs
             | to be spherical). Otherwise one just can't keep track of it
             | and reason about it.
             | 
             | If I need a more precise answer, that's what computer
             | numerics is for.
        
         | melenaboija wrote:
         | 3Blue1Brown series on linear algebra is an amazing resource as
         | a starting point.
         | 
         | https://youtube.com/playlist?list=PL0-GT3co4r2y2YErbmuJw2L5t...
        
           | inetknght wrote:
           | I was going to add my own post recommending 3Blue1Brown. I'm
           | glad you've already recommended it :)
        
           | animal_spirits wrote:
           | Linear algebra is _much_ more complicated than normal algebra
        
           | threatofrain wrote:
           | 3B1B has stated that the series is mostly useful for
           | summarizing or augmenting existing knowledge _after_ taking
           | the class; it 's not for _learning_ Linear Algebra fresh. If
           | you sum all the minutes in the 3B1B videos it 's basically
           | the length of one video from a university course.
        
             | melenaboija wrote:
             | Agree, I said starting point assuming that he has some
             | basic knowledge as he is struggling so he must know
             | something.
             | 
             | For more advanced linear algebra I would recommend the
             | class from Prof. Gilbert at MIT.
             | 
             | https://youtube.com/playlist?list=PLE7DDD91010BC51F8
             | 
             | https://ocw.mit.edu/courses/mathematics/18-06-linear-
             | algebra...
             | 
             | What is your recommendation?
        
               | threatofrain wrote:
               | I'm not sure about recommending video courses because...
               | there are so few people who have taken up the burden of
               | producing a full Linear Algebra video course. It's sad.
               | But I would at least say that whether you're following
               | Gilbert Strang or someone else, you should be following
               | with a book as well.
               | 
               | There's another guy, Jim Hefferon of St Michael's
               | College, who has written a full book for his own class
               | and produced a full video course on Linear Algebra (all
               | free).
               | 
               | https://hefferon.net/linearalgebra/
               | 
               | https://www.youtube.com/watch?v=JnTa9XtvmfI
               | 
               | https://www.youtube.com/watch?v=DJ6YwBN7Ya8
        
               | melenaboija wrote:
               | I totally agree with you and that is why I have also
               | added to the post the link to the open course MIT site.
               | 
               | I also believe that is quite naive thinking that you can
               | learn math in some depth just watching videos (at least
               | with my capacity). For me it is a way to keep some pace
               | and order when learning and, as you say, to find some
               | bibliography and material that is being used by the
               | professor.
        
           | jeffreyrogers wrote:
           | It's good for concepts but you can watch all his videos,
           | think you know what linear algebra is about, and still not
           | know how to calculate anything. You have to do exercises if
           | you want to actually learn math.
        
           | phatfish wrote:
           | I think the sort of visualizations that are around on Youtube
           | are great for those who don't "get" maths easily and need
           | another angle to help them understand. Although 3Blue1Brown
           | is not for beginners there are other beginner resources.
           | 
           | For example, this goes right back to basic algebra but is a
           | very well explained with the afore mentioned visualizations.
           | 
           | Veritasium - How Imaginary Numbers Were Invented
           | https://www.youtube.com/watch?v=cUzklzVXJwo
        
         | RegBarclay wrote:
         | I hadn't thought about it that way. I was good at algebra, but
         | can't get through calculus to save my life. I've mostly found
         | that coding is more about logic than math. When math has come
         | up in my work, it's generally a formula or calculation that's
         | already defined and I just have to code it into a system, which
         | has never been a problem for me.
        
         | ThinkBeat wrote:
         | Algebra is a wide topic.
         | 
         | My second year of university is where i fell off math.
         | 
         | Several people have told me that once they reached post
         | graduate level at university that math made sense to them. They
         | saw the perspective of unified math. How it all fits together.
         | 
         | Sadly, all I did know I have forgotten.
        
         | redman25 wrote:
         | I've enjoyed revisiting topics I learned in school through the
         | Kahn Academy[1]. You can pick any topic you want to start with
         | and follow it through as far as you want.
         | 
         | [1] https://www.khanacademy.org
        
           | web007 wrote:
           | Seconding this.
           | 
           | I went through precalc in school, then promptly forgot most
           | of it once I started working. All of the bits I had learned
           | felt rushed, so a lot of them fell out of my brain even while
           | in school. I only had a basic understanding of most of what I
           | "learned".
           | 
           | About a year ago I decided to go back to basics, and start
           | over from zero on Khan Academy. I've been v.e.r.y slow, maybe
           | a lesson a month on average, but have been grinding through
           | the lowest level math to really understand and remember it.
           | Down to addition, subtraction and multiplication even - I've
           | relearned how to multiply small numbers in my head, and
           | gotten much better at quick mental addition and subtraction.
           | 
           | I have scheduled and dedicated more time for it this year, so
           | I hope to catch up to my original math basis. This time,
           | hopefully, remembering all of it instead of skimming. That
           | should set me up well for linear algebra, and then calculus
           | next year and beyond.
           | 
           | One thing that may help regardless of how you choose to
           | learn: pick a problem you want to tackle that needs Fancy
           | Maths. It doesn't need to be anything useful, or anything
           | difficult like "prove this unproven theorem". It will
           | motivate you as long as it keeps your brain engaged. For me
           | it's factoring and primality proving, where I can't even read
           | the equations / algorithms because I don't have the basic
           | tools. As I get further along I keep looking back to those
           | problems and seeing how the bits I'm learning apply around
           | the edges or to simpler factoring algorithms. It keeps me
           | motivated to learn more to be able to dive deeper into the
           | juicy parts.
        
         | munchbunny wrote:
         | 100% agree this is something you grind at. Calculus, even
         | multivariate, and even the stuff beyond that, still grind. I
         | used to be really good at it, definitely not the best but among
         | the higher scores in my college math classes. But 10+ years
         | later, when I go and look at stuff that would have barely fazed
         | me then, I go cross eyed now. I remember the concepts, vaguely,
         | but following the math and linking together the various
         | theorems and transformations feels like wading through syrup.
         | It's a problem for me as I'm trying to dig into data science
         | stuff, and it feels like getting back into marathon shape after
         | 10 years of not running.
         | 
         | There's absolutely a component of learning the concepts, but a
         | huge part of being good at the math is just building up the
         | mental muscle memory for symbolic manipulation. Sure there's
         | innately talented people out there, but the consistent
         | application of incremental effort will get you very far
         | regardless of talent.
        
         | badactor wrote:
         | The problem for me is identifying where exactly in my
         | mathematical fundamentals things fall apart (like with prime
         | numbers, some basic arithmetic, geometry) that makes higher-
         | level math a struggle conceptually. It's always felt like there
         | were holes in my fundamentals. I suspect the only way to figure
         | this out is to go back and do everything again either through
         | Khan Academy or books. Does anyone else have this issue?
         | 
         | When it comes to math, I try to avoid self-diagnosing with
         | dyscalculia or with poor working memory. Instead, I think I've
         | gone so long with math being an anxiety-inducing subject that
         | any time I need to solve math under the tiniest amounts of
         | pressure, I fall apart.
         | 
         | Mind naming what book you used?
        
           | graycat wrote:
           | Part I
           | 
           | How to get good with math?
           | 
           | Okay. Been there. Done that. Learned a lot of it. Got a Ph.D.
           | in it. Taught it. Applied it. Published peer-reviewed
           | original research in it. Had a good career applying it. Am
           | using it as an advantage in the core of my startup.
           | 
           | Broadly, for a career in computing, at times math can be an
           | advantage, one that might be significant, e.g., get you
           | founder's stock in a startup that becomes successful.
           | 
           | Math and computing can be a career _one-two_ punch: With some
           | math you might find an application, maybe a valuable one, and
           | then with some computing you get to do the associated
           | programming. Maybe then you can show up at work one morning,
           | maybe after doing an _all-nighter_ , and show the final,
           | useful, maybe quite valuable results -- done deal, no
           | waiting, meetings, project approvals, etc.
           | 
           | This is a great time for both math and computing, no doubt
           | unique in all of history. We are awash in what is in
           | historical terms just astounding computing, and part of that
           | is that a lot of math is just a few clicks away at Wikipedia,
           | YouTube, in PDF files from word processing with TeX, etc.
           | 
           | The first thing in math is arithmetic. Of course, current
           | computing eats arithmetic problems much faster than Godzilla
           | eats fish.
           | 
           | You should know basic arithmetic for whole numbers and
           | fractions.
           | 
           | Then you should know the basics of ratios, proportions,
           | percentages, square roots and exponents, logarithms, compound
           | interest, areas, and volumes. E.g., on my instance of Windows
           | 10 Home Edition (that I have as a result of a sad situation,
           | long story), the key in the upper right corner of the
           | keyboard runs ( _opens, launches_ -- maybe computing will
           | think of more silly synonyms) a version of an old scientific-
           | engineering pocket calculator that has a lot of such
           | arithmetic and math.
           | 
           | Uh, that software is harder to learn to use than the math it
           | does! If you can find out how to use such software in less
           | than a few hours of clicking guesses, you can also learn the
           | associated math!
           | 
           | Then on to _algebra_ : That subject is just doing arithmetic
           | with symbols instead of specific values, and that should be
           | really easy for anyone who can write math expressions in a
           | computer language.
           | 
           | Then on to plane geometry: The most important idea there is
           | triangles, especially ones with one angle 90 degrees -- right
           | triangles. Then, sure, the biggie result is the Pythagorean
           | theorem -- it gets applied throughout our economy and has
           | surprisingly far reaching generalizations. For a proof, take
           | 4 of the right triangles and arrange them so that they form a
           | square where each side of the square is the longest side of
           | one of the triangles and all the triangles are inside the
           | square. Then will also see a square in the middle. Then write
           | out the area of the squares and, presto, bingo, get the
           | theorem. There are also 149 or so other proofs.
           | 
           | For a while, I taught trigonometry (about triangles) at
           | Indiana University. The best student in the class was a
           | pretty girl, and later I dated and married her -- see, math
           | can be useful!
           | 
           | Then there is second year algebra where learn some more,
           | e.g., about, say,
           | 
           | (x + y)^n
           | 
           | for numbers x and y and a positive integer n. From that can
           | learn a lot about how many HEADS might get if flip a fair
           | coin 1000 times and can understand the math shown in the
           | baseball movie _Moneyball_. Also that way can start to
           | understand the _bell curve_ of Gauss and the powerful _law of
           | large numbers_.
           | 
           | Might study solid geometry, that is, planes, lines
           | perpendicular to planes, spheres, circles on spheres, etc.
           | 
           | Next up, calculus: As you already know, in a car the
           | speedometer is the rate of change of the odometer. The rate
           | of change of the speedometer is _acceleration_. From Newton
           | 's law of motion F = ma, that is, force is mass times
           | acceleration, in a car you feel the force as you are pressed
           | back in your seat when your Tesla does 0 to 60 MPH in less
           | than 4 seconds! Going around in a circle is also
           | acceleration, and that's why when you make a fast left turn
           | the sack of groceries slides to the right. So, rate of change
           | -- that is the first half of calculus.
           | 
           | Given all the speedometer readings, should be able to
           | reconstruct the odometer readings, and you can: That is the
           | second half of calculus and also is the way both to define
           | and to find the lengths of curved lines (e.g., that the Webb
           | telescope is following), areas and volumes of spheres,
           | cylinders, etc.
           | 
           | How to learn calculus? Long story short, I was not permitted
           | to take calculus yet so got a good calculus book and dug in.
           | Went to a better school and started on their second year
           | calculus and did fine. So, I never took first year calculus
           | -- learned it, taught it, applied it, published research in
           | it, learned math _analysis_ (that calculus is part of) far
           | beyond calculus, but never took a course in it.
           | 
           | How to learn calculus: Get a good book. At each section, (1)
           | study the text and examples and (2) work at least half the
           | exercises, especially the more difficult ones, and check your
           | work with the answers in the back of the book. Don't go for
           | _pre-calculus_ , high school calculus, or high school
           | _advanced placement_ calculus. Instead, just get a good book
           | in CALCULUS. Or get several such books. Then get a quiet
           | place, good light, big chair, clipboard with a sharp, soft
           | mechanical pencil, big, soft eraser and dig in. Since
           | calculus has not changed much in 50+ years, you don 't need a
           | recent book. Instead just do an Internet search of used book
           | sites.
           | 
           | I learned mostly from
           | 
           | Richard E. Johnson and Fred L. Kiokemeister, _Calculus with
           | Analytic Geometry_.
           | 
           | It is VERY well written, even _polished_ , and with an
           | unusually good collection of exercises. When I used it, it
           | was also used at Harvard. You may be able to get a used copy
           | in very good condition for less than $10.
           | 
           | For on-line sources, my opinion is that nearly none of them
           | are good. I've seen a lot of the on-line video sources, and I
           | never saw a good one. E.g., last time I looked at Khan
           | Academy, I concluded that they didn't understand calculus
           | very well.
           | 
           | To learn calculus, or nearly anything in math, whether you
           | are in a course or not, essentially you still need to study
           | as I have outlined. Learning math is not a spectator sport.
           | 
           | If you have taught yourself to be good at C++ and Win32, then
           | you should have NO trouble learning calculus QUITE WELL!
           | 
           | Of COURSE you can teach yourself calculus and nearly anything
           | in math: To keep up, that is what college professors and
           | anyone applying math as a professional do.
        
             | graycat wrote:
             | Part II
             | 
             | If you do much with computer graphics you will encounter
             | matrix theory. That takes you into _linear algebra_ ; next
             | to calculus it is likely the most useful math. Evidence:
             | There are a lot of downloads of LINPACK.
             | 
             | Can start a course in linear algebra by considering solving
             | several equations in several unknowns. The standard
             | technique is _Gauss elimination_ , and can program that in
             | about one page of code. Linear algebra is a good start on
             | curve fitting in statistics and the math of quantum
             | mechanics.
             | 
             | If you want to understand more about cryptography and error
             | correcting codes, you should study _abstract algebra_. Here
             | I would suggest that you actually take a course (a) to help
             | you get through that quite different world of thought and
             | (b) especially to learn how to write proofs. And for (b),
             | take a course where the prof is really good and also
             | carefully reads and comments on your proofs. Abstract
             | algebra is the easy place to learn to write proofs.
             | 
             | Can get more guidance on how to learn math at
             | 
             | https://news.ycombinator.com/item?id=28215105
             | 
             | Somehow long, maybe still, knowledge of both math and
             | computing can be welcome and lucrative in parts of US
             | national security. That was the case early in my career
             | when my annual salary was 6+ times the cost of a new high
             | end Camaro.
             | 
             | Soon FedEx had what their founder, COB, CEO called their
             | "most important problem" -- fleet scheduling. The BoD was
             | concerned, and crucial funding was at risk. I typed
             | furiously, wrote some software, the output "solved" the
             | problem, enabled the funding, and saved FedEx. There, sure,
             | needed to calculate great circle distances so used the law
             | of cosines for spherical triangles -- solid geometry can be
             | good stuff! Also had to handle wind vectors -- linear
             | algebra can be powerful stuff. Then I went off to do much
             | more, _integer linear programming set covering_ where can
             | discover much of the motivation for currently the most
             | important problem in computer science, P versus NP.
             | 
             | Later the BoD wanted some revenue projections. I did a
             | little with some calculus and got a nice answer. Long story
             | short, that work saved FedEx a second time.
             | 
             | For another long story -- I needed to be better at office
             | politics -- I just missed out on some FedEx stock that
             | should be worth ~$500 million now.
             | 
             | The US Navy was collecting ocean wave data at sea, and I
             | was in a software house bidding on writing some software to
             | analyze the data. One customer engineer wanted (a) to know
             | the _power spectrum_ of the ocean waves (that is, what
             | _frequencies_ have the power) and, then, (b) to generate
             | _synthetic_ , _random_ ocean waves with that power
             | spectrum. I quickly read a book by Blackman and Tukey,
             | typed in some software, showed the engineer the results on
             | how to find the power spectra (with an important point
             | about handling low frequencies) and how to generate the
             | synthetic waves, and our company got  "sole source" on the
             | software work.
             | 
             | Later at IBM's Watson research lab, we were doing AI for
             | monitoring of server farms and networks. I thought of
             | another way, for some of the monitoring much more powerful
             | than the AI, based on some original math, and published the
             | results.
             | 
             | Net, some math, especially through calculus and linear
             | algebra, can at times be an important career advantage. For
             | more, get good with probability theory, if you can, the
             | version based on the subject _measure theory_. Then learn
             | some about _stochastic processes_. E.g., once the US Navy
             | wanted an evaluation of the survivability of the US SSBN
             | (missile firing submarines) fleet under a special scenario
             | of global nuclear war limited to sea -- in two weeks. From
             | some old work by B. Koopman, I saw a continuous time,
             | discrete state space Markov process subordinated to a
             | Poisson process, wrote some software, and was done on time.
             | My work got reviewed by a famous mathematician, and he
             | questioned how my software could  "fathom the enormous
             | state space". I answered, at each time, the number of SSBNs
             | surviving is a real valued _random variable_. It is
             | positive and not greater than the number of submarines to
             | begin with so is bounded and has an expectation and a
             | finite variance. Then the law of large numbers applies. So,
             | generate 500 independent sample paths, average them, and
             | get the expectation  "within a gnat's ass nearly all the
             | time". He agreed. I passed the review!
             | 
             | If you go for a Ph.D., then understand that, in the US,
             | academic positions at the better universities are about
             | three things, research, research, and research, especially
             | because that leads to grant money. The _operational_
             | definition of _research_ is that it got published in a
             | peer-reviewed journal. If you publish, say, 3 papers a
             | year, then likely people will stay off your case and you
             | will likely make progress to tenure. People making the
             | promotion and /or funding decisions will rarely look at the
             | papers and, instead, just count them. Papers that result in
             | prizes are usually quite powerful for a career. Generally,
             | though, academics is not very promising for providing a
             | good standard of living and good financial security for you
             | and your family and these days can't hope to compete with
             | what is available in computing, the Internet, etc.
             | 
             | Then the math? It can be an advantage. The "advantage" can
             | have you push ahead, maybe by a little or a lot, useful
             | technology, economic productivity, and civilization. Such
             | progress happens, actually fairly regularly, but is rarely
             | easy. So, if want to push civilization ahead, (a) don't
             | expect that the work will be easy but (b) math can be one
             | of the most powerful advantages.
             | 
             | Now you know some of what I wish I'd known at the beginning
             | of my career. I want a _do-over_ -- where can I apply?
        
           | Kye wrote:
           | https://www.amazon.com/Schaums-Outline-Elementary-
           | Mathematic...
           | 
           | Schaum's Outlines are like that "Learn X in Y Minutes" site
           | for school subjects. They give the clearest, most bare bones
           | explanation so you can quickly identify gaps. I had the
           | college algebra book for the required math class in technical
           | school. Between that and YouTube, I was able to pass the
           | class.
        
           | openknot wrote:
           | For books on strong fundamentals, you can try the Art of
           | Problem Solving series [0]. They suggest a curriculum to
           | start with prealgebra, move to algebra, then counting &
           | probability, then geometry, then precalculus, and finally to
           | calculus (though a regular calculus book like Thomas
           | Calculus/Stewart Calculus/even Spivak/Apostol would work
           | fine).
           | 
           | The main advantage of these books are its focus on building
           | intuition by visualizing shapes or immediately rephrasing
           | notation (e.g. 4/2 is better understood as 4*(1/2), which
           | better explains why you should avoid cases where you divide
           | by zero; I also found their exponent rules easier to
           | understand, because it encourages visualization instead of
           | just memorizing the rules).
           | 
           | The downside is that they're time-consuming due to a large
           | number of exercises (I'm currently still trying to slowly
           | work through them when I can, but if you need higher-level
           | math in the short-term, it's probably better to start there).
           | They're also not a free resource.
           | 
           | For free lecture videos, I've found Professor Leonard's
           | lectures to be excellent, and equivalent to lectures at a
           | university classroom [1].
           | 
           | [0] https://artofproblemsolving.com/store/recommendations
           | 
           | [1] https://www.youtube.com/c/ProfessorLeonard/playlists
        
           | ambrozk wrote:
           | "Mathematical fundamentals" is a sliding scale. You have to
           | define your end goal. What do you want to understand, that
           | you are currently unable to understand due to your incapacity
           | with mathematics?
           | 
           | If you want to understand computational complexity theory,
           | for instance, you need a different set of "fundamentals" than
           | you do if you want to understand high-school physics. It'll
           | be a different thing if you want to read econ papers, and a
           | different thing if you want to study machine learning.
           | 
           | Within the intersection of all these fundamentals is probably
           | basic arithmetic and algebra. Those tools are basic
           | requirements for everything else. Beyond that, you need to
           | define your goal before you decide what math to learn.
        
           | pthread_t wrote:
           | Try Khan Academy. The exercises (especially with how they
           | focus on mastery), coupled with the videos will help you root
           | out your weak points and even master them. Do not be ashamed
           | in starting with the kindergarten math topics and moving
           | upwards from there. If you are able to power through it, good
           | on you. If you get stuck on something, even better -- now is
           | your chance to master it.
           | 
           | KA helped me go from hating math in high school to double
           | majoring in Math & CS in college, and graduating with honors.
           | I donate to KA now.
        
         | corysama wrote:
         | Anyone who sucks at algebra and has a low grind tolerance
         | should try https://dragonbox.com/products/algebra-12 It's very
         | well made. And, it's designed for 12 year olds. So, adults can
         | usually manage to keep up.
        
         | znpy wrote:
         | I'm no math genius however I just want to add this tiny bits:
         | 
         | - you don't really "learn" math, you just get used to it
         | 
         | - math is really mental gymnastics, and "learning math"
         | actually is doing a lot of math exercises
        
         | maxgiraldo wrote:
         | If anyone is looking to brush up on their Algebra fundamentals,
         | I built an app for that and it's free to use:
         | https://apps.apple.com/us/app/pensend/id1571322730. I had a
         | similar problem where I didn't understand where my fundamental
         | knowledge gaps were so I ended up starting from the beginning
         | (pre-algebra). I hope this is helpful for people!
         | 
         | (sorry for the shameless plug)
        
       | thih9 wrote:
       | At what moments do you feel that your math knowledge limits your
       | programming skills?
       | 
       | Also: what kind of programming are you doing? E.g. working with
       | 3d games relies on different math skills than dealing with AB
       | testing.
        
       | jesperlang wrote:
       | I'm currently going through "Math for programmers" (Manning
       | Publ.) and I enjoy it immensely! A lot of math books can feel too
       | abstract and dry but this book was perfect for me coming mostly
       | from a programming background. Start learning learning linear
       | algebra and you will soon find yourself in graphics programming
       | and game engines. That's where I am at the moment and I feel I
       | regained my passion for programming after years in webdev..
        
         | the_hob_code wrote:
         | I completely agree about a lot of math books seeming too
         | abstract. I hated math until I took an interest in physics and
         | realized I needed math to understand the ideas being presented.
         | Suddenly it clicked that the math was actually a way to better
         | represent the ideas, not just a trick for getting answers.
         | Seeing how math applies to create and represent knowledge gave
         | me a huge appreciation for it.
        
       | donenas wrote:
       | Learn the concepts and start practicing
        
       | nerbert wrote:
       | The brilliant app is not bad at this. It takes you through a good
       | learning curve.
        
       | arisbe__ wrote:
       | First Khan Academy, then if you want to go further:
       | 
       | Bill Shillito | Introduction to Higher Mathematics (YouTube
       | lecture course) -
       | https://www.youtube.com/playlist?list=PLZzHxk_TPOStgPtqRZ6Kz...
       | 
       | Richard Hammack | Book of Proof (pdf book) -
       | https://www.people.vcu.edu/~rhammack/BookOfProof/
       | 
       | Taylor Dupuy | Fundamentals of Mathematics (YouTube lecture
       | course) -
       | https://www.youtube.com/playlist?list=PLJmfLfPx1OedcIUn5nSCZ...
       | 
       | Silvanus P Thompson | Calculus Made Easy (html book) -
       | https://calculusmadeeasy.org/ (This shouldn't be your only
       | exposure to Calculus. It is more for building intuition.)
       | 
       | Dana Mosely | Understanding Basic Statistics (YouTube lecture
       | course, no calculus) -
       | https://www.youtube.com/playlist?list=PL9Wxhr5qVFN0WY2CXB4tR...
       | 
       | Gilbert Strang | Highlights of Calculus (YouTube lecture course)
       | - https://www.youtube.com/playlist?list=PLBE9407EA64E2C318
       | 
       | Josh Starmer | StatQuest (Short various statistics videos) -
       | https://www.youtube.com/c/joshstarmer/playlists
       | 
       | Bob Franzosa | Introduction to Topology (single public lecture) -
       | https://www.youtube.com/watch?v=zsN_guq__Ac
       | 
       | Socratica | Abstract Algebra (short videos) -
       | https://www.youtube.com/playlist?list=PLi01XoE8jYoi3SgnnGorR...
       | 
       | MIT Calculus Revisited (Single Variable Calculus):
       | https://www.youtube.com/playlist?list=PL3B08AE665AB9002A
       | 
       | MIT Calculus Revisited (Multivariable Calculus):
       | https://www.youtube.com/playlist?list=PL1C22D4DED943EF7B
       | 
       | MIT Calculus Revisited (Complex Variables, Differential
       | Equations, Linear Algebra):
       | https://www.youtube.com/playlist?list=PLD971E94905A70448
       | 
       | Matthew Macauley | Visual Group Theory, Differential Equations,
       | _Discrete Mathematical Structures_ , Advanced Linear Algebra, and
       | Advanced Engineering Mathematics (YouTube lecture courses) -
       | https://www.youtube.com/channel/UCH1cV4RtgI_N97M8jepiUzw/pla...
       | 
       |  _The Discrete Mathematics course above is probably the most
       | important for your work. In fact I would look for more Discrete
       | Mathematics courses if I were you as it is far more important
       | than anything else here._
       | 
       | Open University (BBC) | Geometric Topology (YouTube lecture
       | course) -
       | https://www.youtube.com/playlist?list=PLKB3Q5Oyy_RNBrS3V2WbO...
       | 
       | Joel David Hamkins | Philosophy of Mathematics (YouTube lecture
       | course) -
       | https://www.youtube.com/playlist?list=PLg5tKDNI_a86OO6J9HuIn...
       | 
       | Marco Taboga | Probability and Statistics & Matrix Algebra (html
       | book, need calculus) - https://www.statlect.com/
       | 
       | On YouTube you can literally watch a good lecture course for just
       | about any typical undergraduate course. You just need to know
       | where to look. Also there are even some really good master's
       | degree courses out there.
       | 
       |  _Of course the only way to really learn the mathematics deeply
       | is to "learn by doing", aka problems and proofs._
       | 
       | Other than the usual big American universities another good
       | source from India is NPTEL (https://nptel.ac.in/course.html).
       | 
       | For somewhat more entertaining short lectures try:
       | 
       | Grant Sanderson | 3Blue1Brown -
       | https://www.youtube.com/c/3blue1brown
       | 
       | Brady Haran | Numberphile -
       | https://www.youtube.com/c/numberphile/
       | 
       | Tai-Danae Bradley, Gabe Perez-Giz, and Kelsey Houston-Edwards |
       | PBS Infinite Series -
       | https://www.youtube.com/c/pbsinfiniteseries/
       | 
       | Raymond Flood (YouTube public lectures at Gresham College) |
       | History of Mathematics -
       | https://www.youtube.com/playlist?list=PL_jwwOG0kPgPPiX0pcbzL...
       | 
       | There are a ton of channels starting to pop up like Grant's 3B1B
       | (I find like a new one every week). He had a contest recently so
       | maybe look at some of the winners.
       | 
       | Lastly this is pretty useful if you get into higher mathematics:
       | 
       | Math Vault | The Definitive Glossary of Higher Mathematical
       | Jargon - https://mathvault.ca/math-glossary/
        
         | RamblingCTO wrote:
         | Saving this for later by commenting it. Many thanks for
         | curating this!
        
           | jesperlang wrote:
           | You can click on the timestamp of the comment and then
           | "favorite" to save it :)
        
         | hiyer wrote:
         | This is an incredibly detailed set of recommendations! Thank
         | you for this :-)
        
         | irchans wrote:
         | Wow, Great, Thanks!
        
       | [deleted]
        
       | secretsatan wrote:
       | I wouldn't say I'm great at math, I scraped an A-Level in it over
       | twenty years ago, didn't use it much for years, but then I got
       | interested in graphics again and there are some severe gaps in my
       | knowledge.
       | 
       | I remember at the time, I just did not understand matrices, I now
       | use them a hell of a lot and I still suck at them. Linear algebra
       | is another one.
       | 
       | Most other stuff day to day stuff I can reasonably understand, or
       | at least sit down with pen and paper and work out what I need to
       | do but the above 2 frequently get my head stuck in knots, I often
       | think about maybe doing a course on these 2
        
       | silicaroach wrote:
       | Identify the concept you don't get and read! Specifically read a
       | _variety_ of explanations on every concept you struggle with.
       | Eventually you will find or form a point of view that will make
       | it clear. There's no easy way, no one source.
        
         | gspr wrote:
         | And while reading: do! And when doing (solving a problem):
         | don't read (the answer)!
        
       | bradleyankrom wrote:
       | I was asking a similar question a few years ago and found Ivan
       | Savov's "No Bullshit Guide to Math & Physics" to be really
       | helpful.
        
         | vmilner wrote:
         | I really like the "placement exam" in this, that tells you
         | where your weaknesses are and what to focus on. I feel like
         | this is the kind of tool I want when someone says "I suck at
         | X".
        
       | jackyinger wrote:
       | The thing about math is that it just boils down to simple rules
       | that have wide ranging consequences and interrelations.
       | 
       | To keep from being overwhelmed, pick a problem and try to focus
       | on only the information relevant to that problem.
       | 
       | I sucked at math as a small child because the social message
       | teachers give that math is hard did not really make sense in
       | light of boring arithmetic so I thought I was missing something.
       | Turns out I wasn't.
       | 
       | Go into it driven by curiosity. Focus on building strong
       | fundamentals; algebra and trigonometry are very useful. Then look
       | into calculus or linear algebra.
       | 
       | Make sure to solve actual problems for practice. But spend plenty
       | of time researching. Take notes. Write out all the steps in your
       | problem solving so that you can debug any mistakes.
       | 
       | Lastly, have fun! There's a lot of neat math out there, treat
       | yourself to some research into whatever is interesting to you
       | when you get sick of grinding on the fundamentals.
        
         | ianai wrote:
         | Yes. I'd encourage people to not be afraid to check out random
         | math topics from wolfram's site. I killed a lot of hours in
         | undergrad that way and it's helpful in non-obvious ways.
        
       | ur-whale wrote:
       | There are a number of facets to this problem.
       | 
       | My own personal experience has been that learning existing math
       | is not very hard and quite fun (YMMV of course and it also
       | depends on how much pre-requisite knowledge is required to even
       | approach the topic)
       | 
       | Once you've acquired the tools, applying them to solve actual
       | engineering problems, also relatively easy (depending on the
       | problem of course) and _very_ fun.
       | 
       | However, solving math problems is a completely different game,
       | and this is where (again for me), the discipline is the most
       | frustrating.
       | 
       | Solving a math problem is like finding a path out of a dense
       | forest, and some people seem to have a "natural compass" guiding
       | them towards it.
       | 
       | For me (born w/o much of a compass), it's always felt like I have
       | to recursively try all possible paths until I find the one that
       | gets me there. Needless to say, if the forest is dense and thick
       | enough, that's a completely hopeless endeavor.
       | 
       | For example, reading the proof to a theorem, assuming it uses
       | tools, concepts and facts you're familiar enough with and does
       | not take giant leaps (the infamous "from here it obviously follow
       | that ...") is easy and can be fun.
       | 
       | But when I get to the QED, I'm always left wondering how the guy
       | who first proved it effing found the path in the first place.
       | 
       | It's borderline disheartening.
        
       | rzarate wrote:
       | I recently faced the same realisation. I'm a software engineer
       | with several years of experience and somehow felt like I didn't
       | know enough about formal computer science/math to tackle the
       | problems I found most interesting (usually very abstract,
       | foundational stuff).
       | 
       | One day I decided to go to a physical bookstore and buy a bunch
       | of books from the Math and Computer Science sections and started
       | from there. It was probably not the best way to start but A START
       | nonetheless. Given that I really enjoyed reading about these
       | topics, I decided to enrol into an online university to pursue a
       | degree in Mathematics.
       | 
       | The book I found the most useful was "How to Prove It"[0]. From
       | my point of view, it was a great starting point for two reasons:
       | * It is approachable (specially for Software Engineers) without
       | being boring. You start building intuitions and it really ignites
       | your curiosity. * It is also sufficient for understanding proves
       | and mathematical notation/language. This is an important building
       | block that will allow you to start tackling the branches in Math
       | you are interested in.
       | 
       | [0] https://www.goodreads.com/book/show/739735.How_to_Prove_It
        
         | danielvaughn wrote:
         | Nice, I'd been looking for a good book that explains the
         | context behind the conventions and thought processes. So many
         | articles/websites/books claim to start out at the basics, but
         | then they toss a bunch of confusing shit at you with barely an
         | explanation. It's very demoralizing. I'll pick this up, thanks
         | for the recommendation.
        
       | slingnow wrote:
       | Have you tried the internet?
       | 
       | Why has there been such a proliferation of these Reddit-style
       | obvious questions upvoted? The front page is full of "Ask HN:
       | what can I do about <insert obvious problem>?"
        
         | WHA8m wrote:
         | Maybe we could link to https://hn.algolia.com more often...
         | 
         | But to be fair, HN is not aiming to be a wiki. It's a vivid
         | forum that discusses topics that are relevant to its
         | participants. Looking at the amount of comments and upvotes on
         | this thread, it's clear that a lot of people are willing to
         | help or engage in some way. Also, people often not only discuss
         | the initial topic (or question) but something else that arose
         | from it. As I said, it's a vivid place. And that's for good.
        
       | brg wrote:
       | Two pieces of advice.
       | 
       | First, pick a topic that you believe you can be fully engaged
       | with. Here are some examples. But you can look at the threads of
       | these from middle school through first year graduate school.
       | 
       | * Geometry (From Euclid to Topology to tensor analysis)
       | 
       | * Linear Algebra (From vectors to Convex Optimization)
       | 
       | * Calculus (Trig to PDEs')
       | 
       | * Algebra (From Groups to Number Theory)
       | 
       | Second, is do the work. With math is easy to trick yourself, in
       | the moment, that you know the solution and understand the
       | concept. But that mistake acrues, you get to a point where
       | everything is opaque and there isn't a starting point without a
       | hint. This feeling of self-assurance needs to be challenged. You
       | need to do the work, rewrite the proofs, do the exercises
       | completely, and explore the concept on your own a bit.
        
       | gaoshan wrote:
       | I'm the same. Self taught, brain is not mathematically oriented
       | and it feels like a gap in my abilities.
       | 
       | People will often say something like, "You don't really need
       | math" for programming but that is missing the point, in my
       | opinion. The point is that it feels to me (after many years of
       | experience and working with many great programmers) that people
       | with a mathematically oriented mind tend to find certain common
       | programming realms easier to grasp. It makes them faster and more
       | productive as they almost intuitively "get" things that are
       | oriented in the same manner as their brain already works.
       | 
       | For others (me) I have much more trouble in these areas and have
       | to really pound my head on the problem to even get close to
       | understanding it as fluently as they do. They probably do not
       | realize this but it's a real struggle (I've had a few occasions
       | where the other person seemed genuinely confused that I was not
       | really "getting it").
        
         | danielvaughn wrote:
         | Same. I definitely don't need math in my day-to-day. But I've
         | been working on this side project for years, and haven't made
         | much progress because I've hit a ceiling that requires math to
         | transcend.
        
       | akomtu wrote:
       | If I were you, I'd study only linear algebra. Other subjects,
       | including calculus, are of little use to programners. The
       | quickest way to learn linear algebra is to pick a high level
       | topic, say... spectral decomposition of a matrix, look it up on
       | wikipedia, see what theorems this topic is made of, and try to
       | repeat the proofs. You'll quickly see that those proofs rely on
       | lower level theorems, so you'll need to look them up too, and so
       | on, until you descend to the definitions of numbers and sets.
        
       | jbot27 wrote:
       | I would say I felt the same way. I am also self taught and just
       | have high school level math. For the most part of my career
       | though it hasn't really been an issue.
       | 
       | But I want to learn ML so digging in. I feel like it is not as
       | bad as I thought it would be, I think the problem with math
       | information is assumes a lot of things. There are tons of
       | notation that is really dense.
       | 
       | My recommendation would be to pick a project or an area, because
       | math is huge. Try to find resources for that. So for ML it is
       | linear algebra and Calculus. Try to find a bunch of resources and
       | get different ways of explaining it.
       | 
       | I highly recommend:
       | 
       | Math for Programmers by Paul Orland
       | 
       | https://betterexplained.com/
        
       | distalx wrote:
       | I'd recommend going through https://www.mathsisfun.com/ website.
       | I'm currently using it for brushing up my algebra and finding it
       | really well phrased.
        
       | hashtones wrote:
       | One interesting fact that you may not know is that the often
       | assumed symbolic notation of algebra (and the rest of
       | mathematics) is fairly recent: that is, the likes of Euler and
       | Fermat were known to write out the entirety of the mathematical
       | logic as a "word problem".
       | 
       | Why I bring this up, is because often I've thought that the
       | innovators of mathematics probably benefited from this action:
       | probably it is what enabled them to solve and derive problems we
       | still today have difficulty resolving.
       | 
       | I bring this up to highlight a point about the philosophical
       | underpinnings of mathematics--that as necessary as it is to
       | understand the syntax and grammar of mathematics today, it is
       | just as necessary to wrestle with the ideas in a form more
       | palpable to your mind: language.
       | 
       | So what I'm saying, really, is that if you find yourself having
       | difficulty with mathematics, as much as it is a matter of "doing
       | the work" (solving the problem, crunching the number) as it is
       | with any other skill, it is as equally important (and maybe even
       | "more" helpful) to approach and take on the logical reasoning as
       | a function of what you can put into words... At least, doing so,
       | I think and hope it would help you render yourself more capable
       | of tackling mathematics.
       | 
       | A good book to start you off in this way, is Bertrand Russel's
       | Introduction to the Mathematical Philosophy. If you have to read
       | it several times, it's been shown rewatching something as higher
       | playerback speed is more effective than just reading it once, so
       | don't be afraid to reread sections (or even in math) as many
       | times as it takes for the knowledge to become explicit to you.
       | 
       | Oh and Khan Academy is a great resource.
       | 
       | Finally, if you have some money you can definitely find a math
       | tutor--if you can find one who you can relate to / who speaks to
       | you, it'll make a radical difference too.
       | 
       | Hope this helps!
       | 
       | Afterward: if you want a problem that'll stump any mathematician,
       | take a look at the Collatz Conjecture: very simple, but
       | understanding it might help you understand how to approach
       | problems in mathematics (although this one has still yet to be
       | proven, and as Paul Erdos said, mathematics is still not yet
       | equiped to prove it, despite how simple it is).
        
       | jyriand wrote:
       | I would go with Art of Problem Solving series. Especially volume
       | 1.
        
       | hdjjhhvvhga wrote:
       | Personal advice: unless you have a very specific reason to do so,
       | completely pass on advanced calculus, real/complex analysis etc.,
       | and continue with discrete maths instead - you will find it
       | immediately useful. Only later, when you find you need it, choose
       | other topics, carefully selected. We only have so much time in
       | life, and the range of fields to study is enormous, so choose
       | wisely. Don't blindly follow the advice of people who will tell
       | you to study everything, you will soon realize it's impossible
       | and it will only leave you sad.
        
       | sjg007 wrote:
       | What do you want to learn? And what area do you want to work in?
       | 
       | From a CS view math is:
       | 
       | Discrete math and combinatorics? Really useful for proving
       | algorithm properties etc.. graph theory is useful as well.
       | 
       | Statistics? Extremely useful. Linear algebra? Extremely useful as
       | applied to statistics and deep learning.
       | 
       | Theorem proving? Useful for determining program correctness,
       | important in some industries.
       | 
       | Of these, I think stats and linear algebra are the most
       | fundamental. You can use these to build models of things and
       | estimate parameters and create predictions.
       | 
       | I think the critical piece is to learn how to apply these
       | tools/concepts correctly to solve problems, determine when they
       | are valid / what the limits are / and how to intellectually debug
       | them.
       | 
       | Otherwise learning about algorithmic complexity and how to solve
       | CS type problems with algorithms is more likely to help your
       | career.
        
       | vasili111 wrote:
       | I would suggest math books from "for Dummies" series if it is
       | hard for you to understand other math books.
        
       | jostylr wrote:
       | I recommend making sure you are good with Guesstimation to start
       | (The book of that name by Weinstein and Adams). Be sure to create
       | your own questions and attempt to answer them. Watch some TED
       | talks and try to use mathematical skepticism to criticize them.
       | Doing all this should make you comfortable using mathematics as a
       | tool. Once you are in that frame of mind, you can explore and
       | have fun with the other topics as ably listed in the other
       | comments on this page. Think of math as a faithful toolkit to
       | explore the world. Once you start to try to describe the world in
       | mathematical language, the more proper tools of mathematics will
       | make much more sense.
       | 
       | Also, keep in mind that pretending things are lines is really
       | useful. See the secant method.
        
       | user_235711 wrote:
       | Any edition of "Mathematical Ideas"[0] might be a good place to
       | start. While it may seem too basic for some, I feel that it
       | covers a lot of concepts and material that are very useful when
       | programming - problem solving, set theory, logic, number theory,
       | basic algebra, etcetera - and does so in a way that is gradually
       | cumulative and not so daunting.
       | 
       | Maybe this book will help you to realize you don't really suck at
       | math, you just had some terrible teachers or whatever. It's also
       | a great introduction to many different mathematical subfields so
       | you can see which ones are most interesting/useful to you for
       | future study.
       | 
       | [0] https://www.amazon.com/Mathematical-Ideas-14th-Charles-
       | Mille...
        
       | bjourne wrote:
       | Khan Academy
        
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