[HN Gopher] Calculus Made Easy by Silvanus P. Thompson (1910)
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       Calculus Made Easy by Silvanus P. Thompson (1910)
        
       Author : avinassh
       Score  : 160 points
       Date   : 2023-10-29 12:15 UTC (10 hours ago)
        
 (HTM) web link (calculusmadeeasy.org)
 (TXT) w3m dump (calculusmadeeasy.org)
        
       | 2OEH8eoCRo0 wrote:
       | My biggest mistake as a SWE (now in my 30s) was not learning
       | higher level mathematics and allowing what knowledge I did
       | possess to wither on the vine.
        
         | fiforpg wrote:
         | What better hobby to pick for those cold winter evenings, than
         | to do some integrals!
         | 
         | Edit: I can recommend this book for a self-guided study
         | 
         | https://archive.org/details/zeldovich-higher-mathematics-for...
         | 
         | The author was a Soviet nuclear physicist (who participated in
         | the creation of the H-bomb), so his main point isn't rigor. It
         | can be a nice change of perspective from standard American
         | texts.
        
           | srvmshr wrote:
           | Although Soviet-era books were notoriously terse & difficult
           | to digest, they had some very aesthetic typesetting. I have
           | owned a few (Problems in Physics by Irodov, & another by
           | Krotov) and they all share similar design aesthetics.
        
         | hotnfresh wrote:
         | Late 30s here. I keep feeling like I should learn math better,
         | but damn, I just never need it. It's much easier to learn stuff
         | I need. As it is, I've lost everything back to about 8th grade
         | math because I've never used any of it, so it's just as gone as
         | all the French I used to know but never found an excuse to use.
         | 
         | [edit] and I'm dreading my kids getting past elementary school
         | math because they're gonna be like "why the hell am I spending
         | months of my life on quadratic equations?" and I'm not gonna
         | have an answer, because IDK why we did that either. At least I
         | have answers for calculus, even if they're not much good ("so
         | you can do physics stuff", "right, but will I ever need to do
         | physics stuff?", "uhhh... unless you really want to, no.")
        
           | mlyle wrote:
           | Quadratics are useful-- finding dimensions of things in the
           | plane; relating area and constrained side lengths, etc. They
           | come up a lot if you want to solve problems.
           | 
           | And good luck taking on calculus without being super solid in
           | the mathematical tools you use against quadratics --
           | factoring, completing squares, manipulation of binomials,
           | pairing up like terms, etc.
        
           | JadeNB wrote:
           | The quadratic equation is completing the square while
           | inexplicably avoiding all the intuition of completing the
           | square. For example, to solve x^2 + 6x + 5 = 0, you would re-
           | write it as (x^2 + 6x + 9) - 4 = 0, which is (x + 3)^2 - 4 =
           | 0 and hence equivalent to (x + 3)^2 = 4, so that x + 3 = +-2
           | and hence x = 3 +- 2 is 1 or 5. Euclid thought of things this
           | way, though his language is, of course, very different to
           | modern language; see, for example, Proposition 6 of Book II (
           | http://aleph0.clarku.edu/~djoyce/elements/bookII/propII6.htm.
           | ..).
           | 
           | That's the same answer as the quadratic formula, but makes a
           | lot more sense to me! Of course I've cooked the numbers so
           | that you don't wind up with surds in the answer, but those
           | are just complications in bookkeeping, not in concept.
        
       | Qem wrote:
       | Silvanus' book makes calculus simple by adopting an infinitesimal
       | approach, like Newton and Leibniz did when they invented
       | calculus. But that approach was shunned by mathematicians for a
       | long time, because it was only made rigorous in the 60s. After
       | Silvanus' book, I also recommend Elementary Calculus: An
       | Infinitesimal Approach, by professor Jerome Keisler, for those
       | interested in this alternative pathway to calculus. It can be
       | freely downloaded at
       | https://people.math.wisc.edu/~hkeisler/calc.html
       | 
       | Relevant wikipedia entry:
       | https://en.m.wikipedia.org/wiki/Nonstandard_analysis
        
         | btilly wrote:
         | I have mixed feelings about this. I've been through nonstandard
         | analysis. My response was, "We shouldn't need the axiom of
         | choice to define the derivative."
         | 
         | But I think that it is extremely important to understand that
         | the infinitesimal notation really MEANS something. Here is some
         | Python to demonstrate.                   # d is a functor. It
         | takes a function and returns a second function.         # The
         | second function captures the change in f over a small distance.
         | # The dx/2 business reduces artefacts of it being a finite
         | distance.         def d (f, dx=0.001):             return
         | lambda t: (f(t + dx/2) - f(t - dx/2))              # d2x / dx2
         | def second_derivative (f):             return lambda t:
         | d(d(f))(t) / (d(x)(t) * d(x)(t))              def x (t):
         | return t              def cubed (t):             return t*t*t
         | print("The second derivative of cubed at 1 is near",
         | second_derivative(cubed)(1))
        
           | btilly wrote:
           | Dang it! I hate re-reading after the time for editing is over
           | and finding a stupid mistake.
           | 
           | The Python is correct, but the comment is not. The formula
           | for the second derivative should be, of course:
           | # d2y / dx2
        
           | finite_depth wrote:
           | Most calculus students don't need the full formal power of
           | rigorous analysis. Calculus, taken alone and with the
           | elementary properties of the real numbers assumed and a few
           | elementary properties of infinitesimals (0 <<<
           | infinitesimal^2 <<< infinitesimal <<< any positive real), can
           | get you a lot of power for very little formal work.
        
             | btilly wrote:
             | Absolutely true. However this comes at the cost of having
             | to not think too hard about issues like "what is a
             | function".
             | 
             | You generally don't run into trouble with 1, x, 1/x, sin(x)
             | and the like. But when you push past the analytic
             | functions, you wind up having to unlearn a lot of ideas so
             | that you can learn an entirely different foundation.
        
               | ezekiel68 wrote:
               | You're right. But then again, lots of scaffolding gets
               | discarded when an arch gets constructed also.
        
           | ZoltanAK2 wrote:
           | You write, "we shouldn't need the axiom of choice to define
           | the derivative."
           | 
           | The good news is that we don't!
           | 
           | Only model-theoretic approaches, which justify the
           | infinitesimal methods by constructing a hyperreal field,
           | require (a weak form of) the axiom of choice [2].
           | 
           | However, there are axioms for nonstandard analysis which are
           | conservative over the usual choice-free set theory ZF. The
           | three axioms of Hrbacek and Katz presented in the article
           | "Infinitesimal analysis without the Axiom of Choice" [1] are
           | the best recent example: these axioms allow you to do
           | everything that is done in Keisler's book and more (including
           | defining the derivative), and you never need to invoke the
           | axiom of choice to justify them.
           | 
           | [1] https://arxiv.org/abs/2009.04980
           | 
           | [2] Essentially, the set of properties satisfied by a fixed
           | nonstandard hypernatural gives rise to a non-principal
           | ultrafilter over the naturals. The axiom of choice is
           | necessary to prove the existence of non-principal
           | ultrafilters in (choice-free) set theory, but the existence
           | of non-principal ultrafilters is not sufficient to prove the
           | axiom of choice.
        
             | btilly wrote:
             | Yeah, yeah. My comment was my reaction 30 years ago.
             | 
             | I find it a mildly interesting intellectual exercise that
             | you can do NSA with weaker axioms than choice. But for all
             | cases I care about, I can already prove it with NSA without
             | ANY additional axioms!
             | 
             | How is this possible? From Shoenfield's absoluteness
             | theorem, you can prove that all statements that an be made
             | in the Peano Axioms that can be proven in ZFC, are also
             | true in ZF. (Note, they must be statable in PA, but not
             | necessarily provable there.) But PA can encode any
             | statement we can make about computation. So take any
             | calculation we can talk about that can be approximated on a
             | computer. We can rewrite it in PA. We can prove it using
             | NSA. We then know that it is true in ZF. And we know that
             | it is true without any additional axioms beyond ZF!
             | 
             | That which we can actually calculate in any useful way can
             | all be calculated on a computer. And therefore NSA can
             | prove anything about Calculus that I care about without
             | needing any axiom beyond ZF.
             | 
             | But in the end this is using a mathematical sledgehammer to
             | drive in a thumb tack. Many approaches to Calculus do not
             | require assertions about the existence of sets that we
             | cannot construct, even in principle. Even though I
             | understand how NSA works, I'd prefer to use any of those.
        
         | dvt wrote:
         | I think I'd also prefer the infinitesimal version of calculus,
         | but the idea of limits is applicable to many other areas of
         | math, not just calculus (evaluating infinite series, for
         | example). So learning limits is probably a better pathway to
         | higher mathematics.
        
           | JadeNB wrote:
           | > I think I'd also prefer the infinitesimal version of
           | calculus, but the idea of limits is applicable to many other
           | areas of math, not just calculus (evaluating infinite series,
           | for example). So learning limits is probably a better pathway
           | to higher mathematics.
           | 
           | I'd say that limits in the sense that you mean (as opposed to
           | category-theoretic limits) are precisely the domain of
           | calculus or, if one wishes so to call it (because one is
           | proving things!), analysis. For example, many US
           | universities, mine included, regard the computation of
           | infinite series as part of Calculus II.
        
           | pfdietz wrote:
           | And non-standard analysis is useful elsewhere in math as
           | well. Here's an example:
           | 
           | https://discreteanalysisjournal.com/article/87772-a-simple-c.
           | ..
        
           | ykonstant wrote:
           | More importantly for this audience, the idea of limits lies
           | at the heart of numerical analysis. Explicating the
           | quantifiers of the definition of a limit is the first step in
           | obtaining control over any estimator of your data. This,
           | among other things, is why I am perpetually baffled at the
           | people _in this audience_ who say that limits is something
           | "they will never need". Limits, their algebra (which subsumes
           | all of high school algebra and inequalities) and their
           | delicate analysis is what makes a ton of numerical algorithms
           | work; Higham's classic has it all, and is perfectly clear
           | about it all.
        
           | btilly wrote:
           | I think that Big O / little o are both more approachable and
           | provide a richer understanding than limits. See, for example,
           | https://micromath.wordpress.com/2008/04/14/donald-knuth-
           | calc... to see Donald Knuth agreeing.
           | 
           | As an example of the conceptual richness, pick up a Calculus
           | book and flip to the problem section for L'Hopital's rule.
           | Without using any special rules at all, attempt to write them
           | out in o-notation and observe that you generally don't need
           | L'Hopital's rule to work them out. It is possible to produce
           | examples that can be calculated by L'Hopital's rule, but not
           | by simply understanding o-notation. But it isn't easy, and
           | you're unlikely to find them in textbooks.
           | 
           | It is probably true that as you go on, limits are more useful
           | in higher mathematics than o-notation. But o-notation is far
           | more useful in most subjects that use mathematics. Given how
           | easy it is to master limits if you know o-notation, why not
           | teach o-notation first?
        
       | analognoise wrote:
       | I think it would be fun to go through all of these books in a
       | group, but to also do worksheets with something like XCas,
       | Maxima, Fricas, etc.
        
       | threatofrain wrote:
       | Consider Analysis 1 by Terry Tao. It walks you from the very
       | beginning and also uses a conversational style. It's one of the
       | most pedagogically smooth or gentle books I've ever read.
        
       | wallflower wrote:
       | My calculus teacher tried to talk me out of taking the AP
       | Calculus AB exam because I wasn't doing that well in his class.
       | "Calculus the Easy Way" which teaches in the setting of a
       | mythical fantasy world where applied problems are solved with
       | calculus unlocked the secret of calculus for me. I ended up
       | scoring a "4" which was a big triumph for me, as it placed me out
       | of taking calculus with all the people who did not want to be
       | taking calculus.
       | 
       | https://www.thriftbooks.com/w/calculus-the-easy-way-easy-way...
        
         | marai2 wrote:
         | Douglas Downing's Trigonometry Made Easy is also a really great
         | book for non-maths people. Same approach of situating
         | Trigonometry in a mythical fantasy land. I remember
         | Trigonometry as a chore of trying to memorize double-angle
         | formulas and such, but this book really helped connect trig in
         | an intuitive way.
         | 
         | I didn't know he had a calculus book, I'll have to check it out
         | now.
        
       | del_operator wrote:
       | I picked this book up when I was learning Algebra to see what the
       | hype was about as a kid. It was dull. I went back to the library
       | stacks after some weeks and found Calculus and Pizza to be even
       | easier to swallow.
       | 
       | Calculus Made Easy is a good book. It made me appreciate even
       | easier books when you need them and have enthusiasm for learning
       | a topic.
        
       | gramie wrote:
       | I graduated from engineering school more than 30 years ago, and
       | learned how to apply calculus without understanding _why_ it
       | worked. This book helped me to finally understand.
        
       | jencuduwvd wrote:
       | Does anyone know any other good resources for learning calculus
       | at home? Preferably ones that show how _and why_. I did some in
       | college but I 've forgotten just about everything, and now I'm
       | finding myself needing it again.
        
         | mindcrime wrote:
         | > Does anyone know any other good resources for learning
         | calculus at home?
         | 
         | Professor Leonard:
         | 
         | Calculus I -
         | https://www.youtube.com/playlist?list=PLF797E961509B4EB5
         | 
         | Calculus II -
         | https://www.youtube.com/playlist?list=PLDesaqWTN6EQ2J4vgsN1H...
         | 
         | Calculus III -
         | https://www.youtube.com/playlist?list=PLDesaqWTN6ESk16YRmzuJ...
         | 
         | I consider him one of the best lecturers in math education, at
         | least for these subjects. And in particular because he is
         | _very_ detailed in his explanations. He points out that most
         | students who struggle with Calculus struggle because they
         | (never mastered | forgot | whatever) their basic _Algebra_. So
         | he does a very thorough job of explaining all of the subtle
         | algebraic manipulations that go on as he works through
         | derivatives, integrals, etc.
         | 
         | TBH, I think a person who wanted to learn the equivalent of
         | high-school algebra could just about doing it by watching his
         | Calc I series... and treat any Calculus they learn as "found
         | money." But assuming you remember at least a little algebra and
         | really want to learn Calculus, I think he's one of the best at
         | teaching it.
         | 
         | Note that most of his lectures are live lectures to an actual
         | class, so IMO the best way to approach it is to pretend you're
         | right there in class. Listen, take notes, and then when he puts
         | an example on the board pause the video and work through the
         | example. Just restart the video when you finish the problem or
         | if you get stuck.
         | 
         | If you want to work additional problems, go on Amazon or
         | Alibris or whatever and buy a cheap used copy of one of the
         | enormous Calculus books, and/or a Shaum's Outlines book on
         | Calculus, or one of those "1001 solved problems in $SUBJECT"
         | books... or some combination of all of the above.
         | 
         | Also as a side-note, speaking for myself, I find that I can
         | follow his material find at 1.25x speed, so I pretty much
         | always watch on 1.25x. I could probably manage 1.5x if I really
         | tried, but the time savings from just doing 1.25x is enough to
         | make me happy. YMMV, of course.
        
         | nerdponx wrote:
         | [delayed]
        
       | xcjs wrote:
       | I love projects like this, but I really wish instead of
       | converting text resources to web sites that these projects would
       | produce epub outputs. It's great for distribution, offline
       | reading, and scaling to different display sizes, aspect ratios,
       | and resolutions.
        
         | MrBlueIncognito wrote:
         | I wonder if there will be a time when textbooks will be created
         | in digital-first format, instead of being mere replicas of what
         | print books are. It doesn't have to be static text and images
         | on A4 pages.
        
         | marcusverus wrote:
         | The page links to a pdf version[0], which can easily be
         | converted to epub using Calibre[0], which is free and open-
         | source.
         | 
         | [0] https://www.gutenberg.org/ebooks/33283
         | 
         | [1] https://calibre-ebook.com/
        
         | Almondsetat wrote:
         | Epubs are horrible for technical documents
        
       | tarkin2 wrote:
       | Has anyone been through the calculus courses on khan academy?
       | What did you think?
        
         | MrBlueIncognito wrote:
         | I went through them a long time ago. It's not the most in-depth
         | resource, but you will learn enough calculus for when you need
         | to actually apply it or even just pass tests. Also learning
         | math on KA is really fun, there's something they just get
         | right. I'd definitely recommend giving it a try.
         | 
         | If you don't feel satisfied after going through the courses,
         | you can always pick up a book afterwards to dig deeper.
        
       | WillAdams wrote:
       | A newer text is:
       | 
       | _Make: Calculus: Build models to learn, visualize, and explore_
       | by Joan Horvath and Rich Cameron
       | 
       | https://www.goodreads.com/book/show/61739368-make
       | 
       | It's part of a series with matching books on Geometry and
       | Trigonometry.
        
       | arbuge wrote:
       | If you don't read anything else in this, read the "Epilogue and
       | Apologue".
        
       | lesona wrote:
       | Would anyone have any recommendations for books/textbooks of this
       | style and the comment's Elementary Calculus: An Infinitesimal
       | Approach, by professor Jerome Keisler on Algebra/PreCalc & Trig?
       | 
       | I've always wanted to learn math but my teachers could never
       | explain it to me in a way that clicked and any textbook I've read
       | couldn't either. These two above really seem to be in my
       | wheelhouse.
        
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       (page generated 2023-10-29 23:00 UTC)