Teaching the Concept of Limit by Using Conceptual Conflict Strategy and Desmos Graphing Calculator
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Limits Involving Infinity (Horizontal and Vertical Asymptotes Revisited)
Limits Involving Infinity (Horizontal and Vertical Asymptotes Revisited) Limits as ‘ x ’ Approaches Infinity At times you’ll need to know the behavior of a function or an expression as the inputs get increasingly larger … larger in the positive and negative directions. We can evaluate this using the limit limf ( x ) and limf ( x ) . x→ ∞ x→ −∞ Obviously, you cannot use direct substitution when it comes to these limits. Infinity is not a number, but a way of denoting how the inputs for a function can grow without any bound. You see limits for x approaching infinity used a lot with fractional functions. 1 Ex) Evaluate lim using a graph. x→ ∞ x A more general version of this limit which will help us out in the long run is this … GENERALIZATION For any expression (or function) in the form CONSTANT , this limit is always true POWER OF X CONSTANT lim = x→ ∞ xn HOW TO EVALUATE A LIMIT AT INFINITY FOR A RATIONAL FUNCTION Step 1: Take the highest power of x in the function’s denominator and divide each term of the fraction by this x power. Step 2: Apply the limit to each term in both numerator and denominator and remember: n limC / x = 0 and lim C= C where ‘C’ is a constant. x→ ∞ x→ ∞ Step 3: Carefully analyze the results to see if the answer is either a finite number or ‘ ∞ ’ or ‘ − ∞ ’ 6x − 3 Ex) Evaluate the limit lim . x→ ∞ 5+ 2 x 3− 2x − 5 x 2 Ex) Evaluate the limit lim . x→ ∞ 2x + 7 5x+ 2 x −2 Ex) Evaluate the limit lim . -
Section 8.8: Improper Integrals
Section 8.8: Improper Integrals One of the main applications of integrals is to compute the areas under curves, as you know. A geometric question. But there are some geometric questions which we do not yet know how to do by calculus, even though they appear to have the same form. Consider the curve y = 1=x2. We can ask, what is the area of the region under the curve and right of the line x = 1? We have no reason to believe this area is finite, but let's ask. Now no integral will compute this{we have to integrate over a bounded interval. Nonetheless, we don't want to throw up our hands. So note that b 2 b Z (1=x )dx = ( 1=x) 1 = 1 1=b: 1 − j − In other words, as b gets larger and larger, the area under the curve and above [1; b] gets larger and larger; but note that it gets closer and closer to 1. Thus, our intuition tells us that the area of the region we're interested in is exactly 1. More formally: lim 1 1=b = 1: b − !1 We can rewrite that as b 2 lim Z (1=x )dx: b !1 1 Indeed, in general, if we want to compute the area under y = f(x) and right of the line x = a, we are computing b lim Z f(x)dx: b !1 a ASK: Does this limit always exist? Give some situations where it does not exist. They'll give something that blows up. -
Calculus for the Life Sciences I Lecture Notes – Limits, Continuity, and the Derivative
Limits Continuity Derivative Calculus for the Life Sciences I Lecture Notes – Limits, Continuity, and the Derivative Joseph M. Mahaffy, [email protected] Department of Mathematics and Statistics Dynamical Systems Group Computational Sciences Research Center San Diego State University San Diego, CA 92182-7720 http://www-rohan.sdsu.edu/∼jmahaffy Spring 2013 Lecture Notes – Limits, Continuity, and the Deriv Joseph M. Mahaffy, [email protected] — (1/24) Limits Continuity Derivative Outline 1 Limits Definition Examples of Limit 2 Continuity Examples of Continuity 3 Derivative Examples of a derivative Lecture Notes – Limits, Continuity, and the Deriv Joseph M. Mahaffy, [email protected] — (2/24) Limits Definition Continuity Examples of Limit Derivative Introduction Limits are central to Calculus Lecture Notes – Limits, Continuity, and the Deriv Joseph M. Mahaffy, [email protected] — (3/24) Limits Definition Continuity Examples of Limit Derivative Introduction Limits are central to Calculus Present definitions of limits, continuity, and derivative Lecture Notes – Limits, Continuity, and the Deriv Joseph M. Mahaffy, [email protected] — (3/24) Limits Definition Continuity Examples of Limit Derivative Introduction Limits are central to Calculus Present definitions of limits, continuity, and derivative Sketch the formal mathematics for these definitions Lecture Notes – Limits, Continuity, and the Deriv Joseph M. Mahaffy, [email protected] — (3/24) Limits Definition Continuity Examples of Limit Derivative Introduction Limits -
13 Limits and the Foundations of Calculus
13 Limits and the Foundations of Calculus We have· developed some of the basic theorems in calculus without reference to limits. However limits are very important in mathematics and cannot be ignored. They are crucial for topics such as infmite series, improper integrals, and multi variable calculus. In this last section we shall prove that our approach to calculus is equivalent to the usual approach via limits. (The going will be easier if you review the basic properties of limits from your standard calculus text, but we shall neither prove nor use the limit theorems.) Limits and Continuity Let {be a function defined on some open interval containing xo, except possibly at Xo itself, and let 1 be a real number. There are two defmitions of the· state ment lim{(x) = 1 x-+xo Condition 1 1. Given any number CI < l, there is an interval (al> b l ) containing Xo such that CI <{(x) ifal <x < b i and x ;6xo. 2. Given any number Cz > I, there is an interval (a2, b2) containing Xo such that Cz > [(x) ifa2 <x< b 2 and x :;Cxo. Condition 2 Given any positive number €, there is a positive number 0 such that If(x) -11 < € whenever Ix - x 0 I< 5 and x ;6 x o. Depending upon circumstances, one or the other of these conditions may be easier to use. The following theorem shows that they are interchangeable, so either one can be used as the defmition oflim {(x) = l. X--->Xo 180 LIMITS AND CONTINUITY 181 Theorem 1 For any given f. -
Hegel on Calculus
HISTORY OF PHILOSOPHY QUARTERLY Volume 34, Number 4, October 2017 HEGEL ON CALCULUS Ralph M. Kaufmann and Christopher Yeomans t is fair to say that Georg Wilhelm Friedrich Hegel’s philosophy of Imathematics and his interpretation of the calculus in particular have not been popular topics of conversation since the early part of the twenti- eth century. Changes in mathematics in the late nineteenth century, the new set-theoretical approach to understanding its foundations, and the rise of a sympathetic philosophical logic have all conspired to give prior philosophies of mathematics (including Hegel’s) the untimely appear- ance of naïveté. The common view was expressed by Bertrand Russell: The great [mathematicians] of the seventeenth and eighteenth cen- turies were so much impressed by the results of their new methods that they did not trouble to examine their foundations. Although their arguments were fallacious, a special Providence saw to it that their conclusions were more or less true. Hegel fastened upon the obscuri- ties in the foundations of mathematics, turned them into dialectical contradictions, and resolved them by nonsensical syntheses. .The resulting puzzles [of mathematics] were all cleared up during the nine- teenth century, not by heroic philosophical doctrines such as that of Kant or that of Hegel, but by patient attention to detail (1956, 368–69). Recently, however, interest in Hegel’s discussion of calculus has been awakened by an unlikely source: Gilles Deleuze. In particular, work by Simon Duffy and Henry Somers-Hall has demonstrated how close Deleuze and Hegel are in their treatment of the calculus as compared with most other philosophers of mathematics. -
Limits and Derivatives 2
57425_02_ch02_p089-099.qk 11/21/08 10:34 AM Page 89 FPO thomasmayerarchive.com Limits and Derivatives 2 In A Preview of Calculus (page 3) we saw how the idea of a limit underlies the various branches of calculus. Thus it is appropriate to begin our study of calculus by investigating limits and their properties. The special type of limit that is used to find tangents and velocities gives rise to the central idea in differential calcu- lus, the derivative. We see how derivatives can be interpreted as rates of change in various situations and learn how the derivative of a function gives information about the original function. 89 57425_02_ch02_p089-099.qk 11/21/08 10:35 AM Page 90 90 CHAPTER 2 LIMITS AND DERIVATIVES 2.1 The Tangent and Velocity Problems In this section we see how limits arise when we attempt to find the tangent to a curve or the velocity of an object. The Tangent Problem The word tangent is derived from the Latin word tangens, which means “touching.” Thus t a tangent to a curve is a line that touches the curve. In other words, a tangent line should have the same direction as the curve at the point of contact. How can this idea be made precise? For a circle we could simply follow Euclid and say that a tangent is a line that intersects the circle once and only once, as in Figure 1(a). For more complicated curves this defini- tion is inadequate. Figure l(b) shows two lines and tl passing through a point P on a curve (a) C. -
Ethnomathematics and Education in Africa
Copyright ©2014 by Paulus Gerdes www.lulu.com http://www.lulu.com/spotlight/pgerdes 2 Paulus Gerdes Second edition: ISTEG Belo Horizonte Boane Mozambique 2014 3 First Edition (January 1995): Institutionen för Internationell Pedagogik (Institute of International Education) Stockholms Universitet (University of Stockholm) Report 97 Second Edition (January 2014): Instituto Superior de Tecnologias e Gestão (ISTEG) (Higher Institute for Technology and Management) Av. de Namaacha 188, Belo Horizonte, Boane, Mozambique Distributed by: www.lulu.com http://www.lulu.com/spotlight/pgerdes Author: Paulus Gerdes African Academy of Sciences & ISTEG, Mozambique C.P. 915, Maputo, Mozambique ([email protected]) Photograph on the front cover: Detail of a Tonga basket acquired, in January 2014, by the author in Inhambane, Mozambique 4 CONTENTS page Preface (2014) 11 Chapter 1: Introduction 13 Chapter 2: Ethnomathematical research: preparing a 19 response to a major challenge to mathematics education in Africa Societal and educational background 19 A major challenge to mathematics education 21 Ethnomathematics Research Project in Mozambique 23 Chapter 3: On the concept of ethnomathematics 29 Ethnographers on ethnoscience 29 Genesis of the concept of ethnomathematics among 31 mathematicians and mathematics teachers Concept, accent or movement? 34 Bibliography 39 Chapter 4: How to recognize hidden geometrical thinking: 45 a contribution to the development of an anthropology of mathematics Confrontation 45 Introduction 46 First example 47 Second example -
Two Fundamental Theorems About the Definite Integral
Two Fundamental Theorems about the Definite Integral These lecture notes develop the theorem Stewart calls The Fundamental Theorem of Calculus in section 5.3. The approach I use is slightly different than that used by Stewart, but is based on the same fundamental ideas. 1 The definite integral Recall that the expression b f(x) dx ∫a is called the definite integral of f(x) over the interval [a,b] and stands for the area underneath the curve y = f(x) over the interval [a,b] (with the understanding that areas above the x-axis are considered positive and the areas beneath the axis are considered negative). In today's lecture I am going to prove an important connection between the definite integral and the derivative and use that connection to compute the definite integral. The result that I am eventually going to prove sits at the end of a chain of earlier definitions and intermediate results. 2 Some important facts about continuous functions The first intermediate result we are going to have to prove along the way depends on some definitions and theorems concerning continuous functions. Here are those definitions and theorems. The definition of continuity A function f(x) is continuous at a point x = a if the following hold 1. f(a) exists 2. lim f(x) exists xœa 3. lim f(x) = f(a) xœa 1 A function f(x) is continuous in an interval [a,b] if it is continuous at every point in that interval. The extreme value theorem Let f(x) be a continuous function in an interval [a,b]. -
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 -
On Mathematics As Sense- Making: an Informalattack on the Unfortunate Divorce of Formal and Informal Mathematics
On Mathematics as Sense Making: An InformalAttack On the Unfortunate Divorce of Formal and Informal 16 Mathematics Alan H. Schoenfeld The University of California-Berkeley This chapter explores the ways that mathematics is understood and used in our culture and the role that schooling plays in shaping those mathematical under standings. One of its goals is to blur the boundaries between forma] and informal mathematics: to indicate that, in real mathematical thinking, formal and informal reasoning are deeply intertwined. I begin, however, by briefly putting on the formalist's hat and defining formal reasoning. As any formalist will tell you, it helps to know what the boundaries are before you try to blur them. PROLOGUE: ON THE LIMITS AND PURITY OF FORMAL REASONING QUA FORMAL REASONING To get to the heart of the matter, formal systems do not denote; that is, formal systems in mathematics are not about anything. Formal systems consist of sets of symbols and rules for manipulating them. As long as you play by the rules, the results are valid within the system. But if you try to apply these systems to something from the real world (or something else), you no longer engage in formal reasoning. You are applying the mathematics at that point. Caveat emp tor: the end result is only as good as the application process. Perhaps the clearest example is geometry. Insofar as most people are con cerned, the plane or solid (Euclidean) geometry studied in secondary school provides a mathematical description of the world they live in and of the way the world must be. -
Notes Chapter 4(Integration) Definition of an Antiderivative
1 Notes Chapter 4(Integration) Definition of an Antiderivative: A function F is an antiderivative of f on an interval I if for all x in I. Representation of Antiderivatives: If F is an antiderivative of f on an interval I, then G is an antiderivative of f on the interval I if and only if G is of the form G(x) = F(x) + C, for all x in I where C is a constant. Sigma Notation: The sum of n terms a1,a2,a3,…,an is written as where I is the index of summation, ai is the ith term of the sum, and the upper and lower bounds of summation are n and 1. Summation Formulas: 1. 2. 3. 4. Limits of the Lower and Upper Sums: Let f be continuous and nonnegative on the interval [a,b]. The limits as n of both the lower and upper sums exist and are equal to each other. That is, where are the minimum and maximum values of f on the subinterval. Definition of the Area of a Region in the Plane: Let f be continuous and nonnegative on the interval [a,b]. The area if a region bounded by the graph of f, the x-axis and the vertical lines x=a and x=b is Area = where . Definition of a Riemann Sum: Let f be defined on the closed interval [a,b], and let be a partition of [a,b] given by a =x0<x1<x2<…<xn-1<xn=b where xi is the width of the ith subinterval. -
Mathematics in Informal Learning Environments: a Summary of the Literature
MATHEMATICS IN INFORMAL LEARNING ENVIRONMENTS: A SUMMARY OF THE LITERATURE Scott Pattison, Andee Rubin, Tracey Wright Updated March 2017 Research on mathematical reasoning and learning has long been a central part of the classroom and formal education literature (e.g., National Research Council, 2001, 2005). However, much less attention has been paid to how children and adults engage with and learn about math outside of school, including everyday settings and designed informal learning environments, such as interactive math exhibits in science centers. With the growing recognition of the importance of informal STEM education (National Research Council, 2009, 2015), researchers, educators, and policymakers are paying more attention to how these experiences might support mathematical thinking and learning and contribute to the broader goal of ensuring healthy, sustainable, economically vibrant communities in this increasingly STEM-rich world. To support these efforts, we conducted a literature review of research on mathematical thinking and learning outside the classroom, in everyday settings and designed informal learning environments. This work was part of the NSF-funded Math in the Making project, led by TERC and the Institute for Learning Innovation and designed to advance researchers’ and educators’ understanding of how to highlight and enhance the mathematics in making experiences.1 Recognizing that the successful integration of mathematics and making requires an understanding of how individuals engage with math in these informal learning environments, we gathered and synthesized the informal mathematics education literature, with the hope that findings would support the Math in the Making project and inform the work of mathematics researchers and educators more broadly.