Ideas of Infinitesimal of Bhaskaracarya in Lilavati and Siddhantasiromani

Total Page:16

File Type:pdf, Size:1020Kb

Ideas of Infinitesimal of Bhaskaracarya in Lilavati and Siddhantasiromani Indian Journal of History of Science, 52.1 (2017) 17-27 DOI: 10.16943/ijhs/2017v52i1/41297 Ideas of Infinitesimals of Bhāskarācārya in Līlāvatī and Siddhāntaśiromanị A B Padmanabha Rao∗ (Received 11 June 2016) Abstract The core concept of Calculus is motivated by the dynamic examples of astronomy dealing with instanta- neous velocities of planets. The first attempt at formalisation of these ideas was made during the periods of Bhāskarācārya and Mādhava and, Isaac Newton and G F Leibniz developing the entire Calculus, and later Cauchy laying the foundation for modern Calculus based on the rigorous treatment of the concept of limit. In this paper Bhāskarācārya's algorithm to deal with expressions involving multiples of zero (treated as infinitesimals) and zero-divisors (zero as divisors), is considered with a brief reference to the similarity it bears with the ideas of Newton and Leibniz. Bhāskarācārya says that this mathematics is of great use in Astronomy.1 Therefore, the infinitesimal concepts suggested in his Līlāvatī and implied in his geometric treat- ment of instantaneous sine-difference equivalent of the differential equation d sin θ = cos θ dθ, (in Leibniz′s notation) are considered in some detail as given in Ganeśadaivajña'ṣ own commentary (Buddhiviāsinī) and his commentary (Vāsanābhāsya)̣ of Siddhāntaśiromanị . Keywords: Calculus, Infinitesimal, Bhāskarācārya, Vāsanābhāsya,̣ Khaguna,̣ Khahara, Fluxion, Limit. 1 INTRODUCTION of inscribed regular polygon of large number of sides leading to the idea of π as a limit of a Though the concept of infinitesimals is a develop- sequence. ment of mathematics of relatively recent times (17th century) it has its roots in the ancient world of 3. The area of a circle as the sum of indefinitely mathematics in the form of intuitive ideas prevalent large number of infinitely small sectors lead- in Greek, Arabic, Chinese and Indian civilizations ing to the idea of integration as a limit of the among others. sum. However, these concepts were of primitive na- These are static examples. The core concept of ture based on geometric ideas such as: Calculus is motivated by the dynamic examples of 1. The tangent as a secant in its limiting position astronomy dealing with instantaneous velocities of leading to the idea of slope as derivative. planets. The earliest development of this was dur- ing the periods of Bhāskarācārya (12th century ce) 2. The circumference as the limit of the perimeter and Mādhava of Kerala School of Mathematics (14th ∗The author was a Professor of Mathematics and Dean of Science Faculty, Walchand College of Arts and Science, Solapur, Maha- rashtra. The article is received from his daughter for considering its publication in IJHS after the demise of the author. 1 The statement found in Vāsanābhāsyạ of Bhāskara while commenting on verse 47 of Līlāvatī goes as follows: अ गणत हगणते महानुपयोगः। 18 INDIAN JOURNAL OF HISTORY OF SCIENCE century ce) and, Sir Isaac Newton and G F Leibniz fluents, the time-rates of changes x˙ and y˙, (17th century ce), the founders of Calculus, and much the fluxions, and xo˙ and yo˙ are the moments of yo˙ later, D'Alembert and Cauchy, who laid the theoret- fluxions,3 o being an infinitesimal. is called ical foundation for modern Calculus without involv- xo˙ the ultimate ratio, thereby implying that o ing infinitesimals. The earlier conceptual difficul- 4 ultimately equals zero, and it[ is] denoted by ties of Calculus were due to the controvertial inde- y˙ y˙ 0 , called the derivative. yo˙ = xo˙ is the terminate form 0 , which arises, for example, from x˙ x˙ the intuitive concept of infinitesimals as explained moment of fluxion y˙. below. Leibniz's Differentials: The infinitesimals of the 2 NEWTON'S NOTIONS OF INFINITESIMALS variables x and y are called the differentials dx and dy, where dy = f ′(x)dx. One may treat Newton calls the variables x and y fluents and them as the ultimate (indivisible) things.5 dy considers them as moving points on a curve, x˙ and is the quotient of differentials or differen- y˙ being rates of motion called fluxions (instanta- dx [ ] dy neous velocities). He calls the products xo˙ and tial coefficient as in dy = dx. This is yo˙ the moments of fluxions (which are in- dx a useful tool where dx (≠ 0) is finite though stantaneous displacements or increments) where o sufficiently small. is infinitesimally small.2 The limit of the ratio yo˙ of ultimate quantities is what he calls as Euler's Differentials: The differential dx can di- xo˙ dy minish indefinitely till it equals6 0. ultimate ratio (the so called ). Since the ratio dx [ ] dy of fluxions is same as that of moments of fluxions, dy = f(x + dx) − f(x) = dx, in later years there was confusion between these two dx terms, and the term fluxion itself was indiscrimi- [ ] dy nately used to denote the increments Hayes, A trea- where can be expressed in the form tise on fluxions. For convenience he denotes xo˙ sim- dx ply by o and yo˙ by f(x+o)−f(x), where y = f(x). ′ ′ yo˙ f (x, 0) dx f (x, 0) 0 The ultimate ratio at o = 0 assumes the indeter- = , xo˙ dx 0 minate form 0 . 0 virtually defined as f ′(x), whereas dy = f ′(x) dx ≠ 0, for practical calculations in Different views of infinitesimals science. This section compares algorithms of Newton, Leib- niz, Euler and Cauchy. Cauchy's Limits: A variable h can diminish indef- initely close enough to 0 called its limit. In Newton's Fluxions: Variables x and y are called symbols: h < ϵ (> 0) or lim h = 0, or h → 0, 2Zero: The Biography of A Dangerous IdeaSeife, Zero: The Biography of A Dangerous Idea. o is the lowercase omicron, the first letter o of the Greek word ouden meaning nothing. Greeks denoted zero by the letter o. Here the word small for all practical purposes means, a small-difference, small enough for the accuracy warranted by the technology of those times. The word `small' in italics, in what follows, is used in this sense. 3Newton's algorithm is given in ``Mathematical Principles of Natural Philosophy'' and Heys's ``Treatise on theory of fuxions''Hayes, A treatise on fluxions. 4Quantities and the ratio of the quantities which in any finite time converge continually to equality and before the end of the time approach nearer the one to the other than by any given difference, become ultimately equal at o = 0 Smith, History of Mathematics. 5The Calculus Gallery, Masterpieces from Newton to LebsegueDunham, The Calculus Gallery, Masterpieces from Newton to Leb- segue, p. 24. 6Calculus GalleryDunham, The Calculus Gallery, Masterpieces from Newton to Lebsegue, p. 53. IDEAS OF INFINITESIMALS OF BHĀSKARĀCĀRYA 19 f(x + h) − f(x) h ≠ 0. can be expressed in notation, 0 is treated as a symbol denoting an in- h finitesimal. The commentator of Bhāskarācārya's al- the form gebra, i.e., text Bījaganitạ , Krṣ ṇ adaivajñạ 8 explains: ′ f (x + hθ)h ′ The idea of infinitesimals by considering a numerical = f (x + hθ), h example. The example presented by Krṣ ṇ adaivajñạ where 0 < θ < 1, h ≠ 0. is shown in the form of a table below. Just as Multiplier Multiplicand Product f(x + h) − f(x) ( ( ( lim = lim f ′(x + hθ) यथा गुणकः) गुः ) गुणनफल) h→zero h h→zero 12 4 48 = f ′(x). 12 3 36 12 2 24 In short we can as well define 12 1 12 12 1/2 6 f(x + h) − f(x) = f ′(x + hθ), h ≠ 0, 12 1/4 3 h 12 1/12 1 = f ′(x), h = 0. He further comments: In the above comparisons the infinitesimal nature of अनयैव युा गु परमापचये small quantities are virtually treated as irrelevant, गुणनफलाप परमापचयेन भा। they being either 0 or not 0, as the case may be. परमापचये तैव पयवतीत े गुे गुणनफलमप मेवेत स। 3 BHĀSKARĀCĀRYA'S NOTIONS OF anayaiva yuktyā gunyasyạ paramā- KHAGUNẠ (MULTIPLE OF ZERO) pacaye gunanaphalasyāpị paramā- pacayena bhāvyam. paramāpacaye It had been the practice to write traditional mathe- śūnyataiva paryavasyatīti śūnye gunyẹ matical works (in Sanskrit) invariably in poetic form. gunanaphalamapị śūnyameveti śid- But a poetic form by its very nature could not ad- dham. mit the mathematical symbolism and therefore the author had to resort to algorithmic style. Though By the same logic, if the multiplicand Bhāskarācārya has himself written a commentary (gunyạ ) becomes smaller and smaller so on the astronomical part of his monumental work does the product (gunanaphalạ ) which Siddhāntaśiromanị , in the case of Līlāvatī and Bī- ultimately becomes the smallest (i.e., jaganita,̣ being basic mathematics necessary for his zero) as the multiplicand becomes the work, the demonstrations of proof and the details of smallest. workings were left to the wisdom of eminent com- Similarly this logic is applicable to the multiplier. mentators (such as Ganeśadaivajñạ and Krṣ ṇ adaiva-̣ Thus x0 is treated as an infinitesimal, ever decreas- jña), teachers and gifted students, lest it be too volu- ing quantity, attaining the value zero. Therefore it is 7 minous. natural to define x0 as zero. In modern notation: lim x0 = zero, and [x0]0=zero = zero. 3.1 Ideas of infinitesimals 0→zero Bhāskarācārya's multiple of zero khagunạ , x0, is the The idea of limit is conveyed by Buddhivilāsinī 9 as counterpart of moment of fluxion. For lack of proper follows: 7SiddhāntaśiromanịSastry, Siddhāntaśiromanị of Bhāskarācārya with Vāsanābhāsyạ , p. 39, śloka 9, Somayaji, Siddhāntaśiromanị of Bhāskarācārya, p. 99, Bhāskarācārya says that he has made his work neither voluminous nor brief, for both the intelligent and the less gifted are to be enlightened.
Recommended publications
  • Year 6 Local Linearity and L'hopitals.Notebook December 04, 2018
    Year 6 Local Linearity and L'Hopitals.notebook December 04, 2018 New Divider! ­ Application of Derivatives: Local Linearity and L'Hopitals Local Linear Approximation Do Now: For each sketch the function, write the equation of the tangent line at x = 0 and include the tangent line in your sketch. 1) 2) In general, if a function f is differentiable at an x, then a sufficiently magnified portion of the graph of f centered at the point P(x, f(x)) takes on the appearance of a ______________ line segment. For this reason, a function that is differentiable at x is sometimes said to be locally linear at x. 1 Year 6 Local Linearity and L'Hopitals.notebook December 04, 2018 How is this useful? We are pretty good at finding the equations of tangent lines for various functions. Question: Would you rather evaluate linear functions or crazy ridiculous functions such as higher order polynomials, trigonometric, logarithmic, etc functions? Evaluate sec(0.3) The idea is to use the equation of the tangent line to a point on the curve to help us approximate the function values at a specific x. Get it??? Probably not....here is an example of a problem I would like us to be able to approximate by the end of the class. Without the use of a calculator approximate . 2 Year 6 Local Linearity and L'Hopitals.notebook December 04, 2018 Local Linear Approximation General Proof Directions would say, evaluate f(a). If f(x) you find this impossible for some y reason, then that's how you would recognize we need to use local linear approximation! You would: 1) Draw in a tangent line at x = a.
    [Show full text]
  • 0.999… = 1 an Infinitesimal Explanation Bryan Dawson
    0 1 2 0.9999999999999999 0.999… = 1 An Infinitesimal Explanation Bryan Dawson know the proofs, but I still don’t What exactly does that mean? Just as real num- believe it.” Those words were uttered bers have decimal expansions, with one digit for each to me by a very good undergraduate integer power of 10, so do hyperreal numbers. But the mathematics major regarding hyperreals contain “infinite integers,” so there are digits This fact is possibly the most-argued- representing not just (the 237th digit past “Iabout result of arithmetic, one that can evoke great the decimal point) and (the 12,598th digit), passion. But why? but also (the Yth digit past the decimal point), According to Robert Ely [2] (see also Tall and where is a negative infinite hyperreal integer. Vinner [4]), the answer for some students lies in their We have four 0s followed by a 1 in intuition about the infinitely small: While they may the fifth decimal place, and also where understand that the difference between and 1 is represents zeros, followed by a 1 in the Yth less than any positive real number, they still perceive a decimal place. (Since we’ll see later that not all infinite nonzero but infinitely small difference—an infinitesimal hyperreal integers are equal, a more precise, but also difference—between the two. And it’s not just uglier, notation would be students; most professional mathematicians have not or formally studied infinitesimals and their larger setting, the hyperreal numbers, and as a result sometimes Confused? Perhaps a little background information wonder .
    [Show full text]
  • Understanding Student Use of Differentials in Physics Integration Problems
    PHYSICAL REVIEW SPECIAL TOPICS - PHYSICS EDUCATION RESEARCH 9, 020108 (2013) Understanding student use of differentials in physics integration problems Dehui Hu and N. Sanjay Rebello* Department of Physics, 116 Cardwell Hall, Kansas State University, Manhattan, Kansas 66506-2601, USA (Received 22 January 2013; published 26 July 2013) This study focuses on students’ use of the mathematical concept of differentials in physics problem solving. For instance, in electrostatics, students need to set up an integral to find the electric field due to a charged bar, an activity that involves the application of mathematical differentials (e.g., dr, dq). In this paper we aim to explore students’ reasoning about the differential concept in physics problems. We conducted group teaching or learning interviews with 13 engineering students enrolled in a second- semester calculus-based physics course. We amalgamated two frameworks—the resources framework and the conceptual metaphor framework—to analyze students’ reasoning about differential concept. Categorizing the mathematical resources involved in students’ mathematical thinking in physics provides us deeper insights into how students use mathematics in physics. Identifying the conceptual metaphors in students’ discourse illustrates the role of concrete experiential notions in students’ construction of mathematical reasoning. These two frameworks serve different purposes, and we illustrate how they can be pieced together to provide a better understanding of students’ mathematical thinking in physics. DOI: 10.1103/PhysRevSTPER.9.020108 PACS numbers: 01.40.Àd mathematical symbols [3]. For instance, mathematicians I. INTRODUCTION often use x; y asR variables and the integrals are often written Mathematical integration is widely used in many intro- in the form fðxÞdx, whereas in physics the variables ductory and upper-division physics courses.
    [Show full text]
  • Leonhard Euler: His Life, the Man, and His Works∗
    SIAM REVIEW c 2008 Walter Gautschi Vol. 50, No. 1, pp. 3–33 Leonhard Euler: His Life, the Man, and His Works∗ Walter Gautschi† Abstract. On the occasion of the 300th anniversary (on April 15, 2007) of Euler’s birth, an attempt is made to bring Euler’s genius to the attention of a broad segment of the educated public. The three stations of his life—Basel, St. Petersburg, andBerlin—are sketchedandthe principal works identified in more or less chronological order. To convey a flavor of his work andits impact on modernscience, a few of Euler’s memorable contributions are selected anddiscussedinmore detail. Remarks on Euler’s personality, intellect, andcraftsmanship roundout the presentation. Key words. LeonhardEuler, sketch of Euler’s life, works, andpersonality AMS subject classification. 01A50 DOI. 10.1137/070702710 Seh ich die Werke der Meister an, So sehe ich, was sie getan; Betracht ich meine Siebensachen, Seh ich, was ich h¨att sollen machen. –Goethe, Weimar 1814/1815 1. Introduction. It is a virtually impossible task to do justice, in a short span of time and space, to the great genius of Leonhard Euler. All we can do, in this lecture, is to bring across some glimpses of Euler’s incredibly voluminous and diverse work, which today fills 74 massive volumes of the Opera omnia (with two more to come). Nine additional volumes of correspondence are planned and have already appeared in part, and about seven volumes of notebooks and diaries still await editing! We begin in section 2 with a brief outline of Euler’s life, going through the three stations of his life: Basel, St.
    [Show full text]
  • Calculus Terminology
    AP Calculus BC Calculus Terminology Absolute Convergence Asymptote Continued Sum Absolute Maximum Average Rate of Change Continuous Function Absolute Minimum Average Value of a Function Continuously Differentiable Function Absolutely Convergent Axis of Rotation Converge Acceleration Boundary Value Problem Converge Absolutely Alternating Series Bounded Function Converge Conditionally Alternating Series Remainder Bounded Sequence Convergence Tests Alternating Series Test Bounds of Integration Convergent Sequence Analytic Methods Calculus Convergent Series Annulus Cartesian Form Critical Number Antiderivative of a Function Cavalieri’s Principle Critical Point Approximation by Differentials Center of Mass Formula Critical Value Arc Length of a Curve Centroid Curly d Area below a Curve Chain Rule Curve Area between Curves Comparison Test Curve Sketching Area of an Ellipse Concave Cusp Area of a Parabolic Segment Concave Down Cylindrical Shell Method Area under a Curve Concave Up Decreasing Function Area Using Parametric Equations Conditional Convergence Definite Integral Area Using Polar Coordinates Constant Term Definite Integral Rules Degenerate Divergent Series Function Operations Del Operator e Fundamental Theorem of Calculus Deleted Neighborhood Ellipsoid GLB Derivative End Behavior Global Maximum Derivative of a Power Series Essential Discontinuity Global Minimum Derivative Rules Explicit Differentiation Golden Spiral Difference Quotient Explicit Function Graphic Methods Differentiable Exponential Decay Greatest Lower Bound Differential
    [Show full text]
  • Infinitesimal Calculus
    Infinitesimal Calculus Δy ΔxΔy and “cannot stand” Δx • Derivative of the sum/difference of two functions (x + Δx) ± (y + Δy) = (x + y) + Δx + Δy ∴ we have a change of Δx + Δy. • Derivative of the product of two functions (x + Δx)(y + Δy) = xy + Δxy + xΔy + ΔxΔy ∴ we have a change of Δxy + xΔy. • Derivative of the product of three functions (x + Δx)(y + Δy)(z + Δz) = xyz + Δxyz + xΔyz + xyΔz + xΔyΔz + ΔxΔyz + xΔyΔz + ΔxΔyΔ ∴ we have a change of Δxyz + xΔyz + xyΔz. • Derivative of the quotient of three functions x Let u = . Then by the product rule above, yu = x yields y uΔy + yΔu = Δx. Substituting for u its value, we have xΔy Δxy − xΔy + yΔu = Δx. Finding the value of Δu , we have y y2 • Derivative of a power function (and the “chain rule”) Let y = x m . ∴ y = x ⋅ x ⋅ x ⋅...⋅ x (m times). By a generalization of the product rule, Δy = (xm−1Δx)(x m−1Δx)(x m−1Δx)...⋅ (xm −1Δx) m times. ∴ we have Δy = mx m−1Δx. • Derivative of the logarithmic function Let y = xn , n being constant. Then log y = nlog x. Differentiating y = xn , we have dy dy dy y y dy = nxn−1dx, or n = = = , since xn−1 = . Again, whatever n−1 y dx x dx dx x x x the differentials of log x and log y are, we have d(log y) = n ⋅ d(log x), or d(log y) n = . Placing these values of n equal to each other, we obtain d(log x) dy d(log y) y dy = .
    [Show full text]
  • March 14 Math 1190 Sec. 62 Spring 2017
    March 14 Math 1190 sec. 62 Spring 2017 Section 4.5: Indeterminate Forms & L’Hopital’sˆ Rule In this section, we are concerned with indeterminate forms. L’Hopital’sˆ Rule applies directly to the forms 0 ±∞ and : 0 ±∞ Other indeterminate forms we’ll encounter include 1 − 1; 0 · 1; 11; 00; and 10: Indeterminate forms are not defined (as numbers) March 14, 2017 1 / 61 Theorem: l’Hospital’s Rule (part 1) Suppose f and g are differentiable on an open interval I containing c (except possibly at c), and suppose g0(x) 6= 0 on I. If lim f (x) = 0 and lim g(x) = 0 x!c x!c then f (x) f 0(x) lim = lim x!c g(x) x!c g0(x) provided the limit on the right exists (or is 1 or −∞). March 14, 2017 2 / 61 Theorem: l’Hospital’s Rule (part 2) Suppose f and g are differentiable on an open interval I containing c (except possibly at c), and suppose g0(x) 6= 0 on I. If lim f (x) = ±∞ and lim g(x) = ±∞ x!c x!c then f (x) f 0(x) lim = lim x!c g(x) x!c g0(x) provided the limit on the right exists (or is 1 or −∞). March 14, 2017 3 / 61 The form 1 − 1 Evaluate the limit if possible 1 1 lim − x!1+ ln x x − 1 March 14, 2017 4 / 61 March 14, 2017 5 / 61 March 14, 2017 6 / 61 Question March 14, 2017 7 / 61 l’Hospital’s Rule is not a ”Fix-all” cot x Evaluate lim x!0+ csc x March 14, 2017 8 / 61 March 14, 2017 9 / 61 Don’t apply it if it doesn’t apply! x + 4 6 lim = = 6 x!2 x2 − 3 1 BUT d (x + 4) 1 1 lim dx = lim = x!2 d 2 x!2 2x 4 dx (x − 3) March 14, 2017 10 / 61 Remarks: I l’Hopital’s rule only applies directly to the forms 0=0, or (±∞)=(±∞).
    [Show full text]
  • Chapter 4 Differentiation in the Study of Calculus of Functions of One Variable, the Notions of Continuity, Differentiability and Integrability Play a Central Role
    Chapter 4 Differentiation In the study of calculus of functions of one variable, the notions of continuity, differentiability and integrability play a central role. The previous chapter was devoted to continuity and its consequences and the next chapter will focus on integrability. In this chapter we will define the derivative of a function of one variable and discuss several important consequences of differentiability. For example, we will show that differentiability implies continuity. We will use the definition of derivative to derive a few differentiation formulas but we assume the formulas for differentiating the most common elementary functions are known from a previous course. Similarly, we assume that the rules for differentiating are already known although the chain rule and some of its corollaries are proved in the solved problems. We shall not emphasize the various geometrical and physical applications of the derivative but will concentrate instead on the mathematical aspects of differentiation. In particular, we present several forms of the mean value theorem for derivatives, including the Cauchy mean value theorem which leads to L’Hôpital’s rule. This latter result is useful in evaluating so called indeterminate limits of various kinds. Finally we will discuss the representation of a function by Taylor polynomials. The Derivative Let fx denote a real valued function with domain D containing an L ? neighborhood of a point x0 5 D; i.e. x0 is an interior point of D since there is an L ; 0 such that NLx0 D. Then for any h such that 0 9 |h| 9 L, we can define the difference quotient for f near x0, fx + h ? fx D fx : 0 0 4.1 h 0 h It is well known from elementary calculus (and easy to see from a sketch of the graph of f near x0 ) that Dhfx0 represents the slope of a secant line through the points x0,fx0 and x0 + h,fx0 + h.
    [Show full text]
  • Leonhard Euler - Wikipedia, the Free Encyclopedia Page 1 of 14
    Leonhard Euler - Wikipedia, the free encyclopedia Page 1 of 14 Leonhard Euler From Wikipedia, the free encyclopedia Leonhard Euler ( German pronunciation: [l]; English Leonhard Euler approximation, "Oiler" [1] 15 April 1707 – 18 September 1783) was a pioneering Swiss mathematician and physicist. He made important discoveries in fields as diverse as infinitesimal calculus and graph theory. He also introduced much of the modern mathematical terminology and notation, particularly for mathematical analysis, such as the notion of a mathematical function.[2] He is also renowned for his work in mechanics, fluid dynamics, optics, and astronomy. Euler spent most of his adult life in St. Petersburg, Russia, and in Berlin, Prussia. He is considered to be the preeminent mathematician of the 18th century, and one of the greatest of all time. He is also one of the most prolific mathematicians ever; his collected works fill 60–80 quarto volumes. [3] A statement attributed to Pierre-Simon Laplace expresses Euler's influence on mathematics: "Read Euler, read Euler, he is our teacher in all things," which has also been translated as "Read Portrait by Emanuel Handmann 1756(?) Euler, read Euler, he is the master of us all." [4] Born 15 April 1707 Euler was featured on the sixth series of the Swiss 10- Basel, Switzerland franc banknote and on numerous Swiss, German, and Died Russian postage stamps. The asteroid 2002 Euler was 18 September 1783 (aged 76) named in his honor. He is also commemorated by the [OS: 7 September 1783] Lutheran Church on their Calendar of Saints on 24 St. Petersburg, Russia May – he was a devout Christian (and believer in Residence Prussia, Russia biblical inerrancy) who wrote apologetics and argued Switzerland [5] forcefully against the prominent atheists of his time.
    [Show full text]
  • Arxiv:1404.5658V1 [Math.LO] 22 Apr 2014 03F55
    TOWARD A CLARITY OF THE EXTREME VALUE THEOREM KARIN U. KATZ, MIKHAIL G. KATZ, AND TARAS KUDRYK Abstract. We apply a framework developed by C. S. Peirce to analyze the concept of clarity, so as to examine a pair of rival mathematical approaches to a typical result in analysis. Namely, we compare an intuitionist and an infinitesimal approaches to the extreme value theorem. We argue that a given pre-mathematical phenomenon may have several aspects that are not necessarily captured by a single formalisation, pointing to a complementar- ity rather than a rivalry of the approaches. Contents 1. Introduction 2 1.1. A historical re-appraisal 2 1.2. Practice and ontology 3 2. Grades of clarity according to Peirce 4 3. Perceptual continuity 5 4. Constructive clarity 7 5. Counterexample to the existence of a maximum 9 6. Reuniting the antipodes 10 7. Kronecker and constructivism 11 8. Infinitesimal clarity 13 8.1. Nominalistic reconstructions 13 8.2. Klein on rivalry of continua 14 arXiv:1404.5658v1 [math.LO] 22 Apr 2014 8.3. Formalizing Leibniz 15 8.4. Ultrapower 16 9. Hyperreal extreme value theorem 16 10. Approaches and invitations 18 11. Conclusion 19 References 19 2000 Mathematics Subject Classification. Primary 26E35; 00A30, 01A85, 03F55. Key words and phrases. Benacerraf, Bishop, Cauchy, constructive analysis, con- tinuity, extreme value theorem, grades of clarity, hyperreal, infinitesimal, Kaestner, Kronecker, law of excluded middle, ontology, Peirce, principle of unique choice, procedure, trichotomy, uniqueness paradigm. 1 2 KARINU. KATZ, MIKHAILG. KATZ, ANDTARASKUDRYK 1. Introduction German physicist G. Lichtenberg (1742 - 1799) was born less than a decade after the publication of the cleric George Berkeley’s tract The Analyst, and would have certainly been influenced by it or at least aware of it.
    [Show full text]
  • Indeterminate Forms and Improper Integrals
    CHAPTER 8 Indeterminate Forms and Improper Integrals 8.1. L’Hopital’ˆ s Rule ¢ To begin this section, we return to the material of section 2.1, where limits are defined. Suppose f ¡ x is a function defined in an interval around a, but not necessarily at a. Then we write ¢¥¤ (8.1) lim f ¡ x L x £ a ¢ if we can insure that f ¡ x is as close as we please to L just by taking x close enough to a. If f is also defined at a, and ¢¦¤ ¡ ¢ (8.2) lim f ¡ x f a x £ a ¢ we say that f is continuous at a (we urge the reader to review section 2.1). If the expression for f ¡ x is a polynomial, we found limits by just substituting a for x; this works because polynomials are continuous. ¢ But how do we calculate limits when the expression f ¡ x cannot be determined at a? For example, we recall the definition of the derivative: ¢ ¡ ¢ f ¡ x f a ¢©¤ (8.3) f §¨¡ x lim £ x a x a The value cannot be determined by simply evaluating at x ¤ a, because both numerator and denominator ¢ ¡ ¢ are 0 at a. This is an example of an indeterminate form of type 0/0: an expression f ¡ x g x , where both ¢ ¡ ¢ ¡ ¢ f ¡ a and g a are zero. As for 8.3, in case f x is a polynomial, we found the limit by long division, and then evaluating the quotient at a (see Theorem 1.1). For trigonometric functions, we devised a geometric argument to calculate the limit (see Proposition 2.7).
    [Show full text]
  • Infinitesimal: How a Dangerous Mathematical Theory Shaped the Modern World Reviewed by Slava Gerovitch
    BOOK REVIEW Infinitesimal: How a Dangerous Mathematical Theory Shaped the Modern World Reviewed by Slava Gerovitch Infinitesimal: How a Dangerous Mathematical Theory ing, from the chaos of imprecise analogies to the order Shaped the Modern World of disciplined reasoning. Yet, as Amir Alexander argues Amir Alexander in his fascinating book Infinitesimal: How a Dangerous Scientific American/Farrar, Straus and Giroux, April 2014 Mathematical Theory Shaped the Modern World, it was US$27.00/US$16.00, 368 pages precisely the champions of offensive infinitesimals who Hardcover ISBN-13: 978-0-37-417681-5 propelled mathematics forward, while the rational critics Paperback ISBN-13: 978-0-37-453499-8 slowed the development of mathematical thought. More- over, the debate over infinitesimals reflected a larger clash From today’s perspective, a mathematical technique that in European culture between religious dogma and intellec- lacks rigor or leads to paradoxes is a contradiction in tual pluralism and between the proponents of traditional terms. It must be expelled from mathematics, lest it dis- order and the defenders of new liberties. credit the profession, sow chaos, and put a large stain on Known since antiquity, the concept of indivisibles gave the shining surface of eternal truth. This is precisely what rise to Zeno’s paradoxes, including the famous “Achilles the leading mathematicians of the most learned Catholic and the Tortoise” conundrum, and was subjected to scath- order, the Jesuits, said about the “method of indivisibles”, ing philosophical critique by Plato and Aristotle. Archime- a dubious procedure of calculating areas and volumes by des used the method of indivisibles with considerable suc- representing plane figures or solids as a composition of in- cess, but even he, once a desired volume was calculated, divisible lines or planes, “infinitesimals”.
    [Show full text]