A History of Trigonometry Education in the United States: 1776-1900

Total Page:16

File Type:pdf, Size:1020Kb

A History of Trigonometry Education in the United States: 1776-1900 A History of Trigonometry Education in the United States: 1776-1900 Jenna Van Sickle Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy under the Executive Committee of the Graduate School of Arts and Sciences COLUMBIA UNIVERSITY 2011 ©2011 Jenna Van Sickle All Rights Reserved ABSTRACT A History of Trigonometry Education in the United States: 1776-1900 Jenna Van Sickle This dissertation traces the history of the teaching of elementary trigonometry in United States colleges and universities from 1776 to 1900. This study analyzes textbooks from the eighteenth and nineteenth centuries, reviews in contemporary periodicals, course catalogs, and secondary sources. Elementary trigonometry was a topic of study in colleges throughout this time period, but the way in which trigonometry was taught and defined changed drastically, as did the scope and focus of the subject. Because of advances in analytic trigonometry by Leonhard Euler and others in the seventeenth and eighteenth centuries, the trigonometric functions came to be defined as ratios, rather than as line segments. This change came to elementary trigonometry textbooks beginning in antebellum America and the ratios came to define trigonometric functions in elementary trigonometry textbooks by the end of the nineteenth century. During this time period, elementary trigonometry textbooks grew to have a much more comprehensive treatment of the subject and considered trigonometric functions in many different ways. In the late eighteenth century, trigonometry was taught as a topic in a larger mathematics course and was used only to solve triangles for applications in surveying and navigation. Textbooks contained few pedagogical tools and only the most basic of trigonometric formulas. By the end of the nineteenth century, trigonometry was taught as its own course that covered the topic extensively with many applications to real life. Textbooks were full of pedagogical tools. The path that the teaching of trigonometry took through the late eighteenth and nineteenth centuries did not always move in a linear fashion. Sometimes trigonometry education stayed the same for a long time and then was suddenly changed, but other times changes happened more gradually. There were many international influences, and there were many influential Americans and influential American institutions that changed the course of trigonometry instruction in this country. This dissertation follows the path of those changes from 1776 to 1900. After 1900, trigonometry instruction became a topic of secondary education rather than higher education. Table of Contents Chapter I: Introduction…………………………………………………………….. 1 Need for the Study………………………………………………................ 1 Purpose of the Study……………………………………………................. 3 Procedures of the Study…………………………………………................ 4 Chapter II: Literature Review……………………………………………………… 7 The History of Mathematics Education…………………………………… 10 References that Directly Inform this Study………………………………. 10 Allen‘s Teaching of Trigonometry………………………………………... 22 Mathematics Education References for Methodology……………………. 23 Overview of the History of Trigonometry………………………………… 32 ―Historical Reflections on the Teaching of Trigonometry‖………………. 40 Resources on the History of Trigonometry……………………………….. 43 The History of Higher Education…………………………………………. 46 Summary and Synthesis…………………………………………………… 55 From the ―Line System‖ to the ―Ratio System‖…………………………... 56 Textbook Adoption in Colleges and Universities………………................. 57 The French and European Influences……………………………………... 58 Chapter III: Methodology…………………………………………………………. 59 Methods for Historical Research………………………………………….. 59 Methods for History of Mathematics Education…………………………. 61 Methods for Textbook Analysis…………………………………………... 65 Summary…………………………………………………………………... 67 Chapter IV: The Early Establishment of Trigonometry Education………………... 68 A Note on Terminology…………………………………………………… 69 On the Construction of Trigonometric Tables…………………………….. 71 Eighteenth and Early Nineteenth Century Teaching of Trigonometry……. 72 English Textbooks………………………………………………………… 73 Scottish Textbooks………………………………………………………... 84 American Textbooks………………………………………………………. 87 Trends in Textbooks—English, Scottish, and American…………………. 92 Summary…………………………………………………………………... 100 i Chapter V: Antebellum Trigonometry Education…………………………………. 103 A Note on Terminology…………………………………………………… 104 Early to Mid-Nineteenth Century Teaching of Trigonometry…………….. 105 French Textbooks…………………………………………………………. 106 Translations and Adaptations of French Textbooks………………………. 108 Liberal Translations and Adaptations of French Textbooks……………… 116 American Textbooks………………………………………………………. 118 New Pedagogy Takes Shape………………………………………………. 128 Changes in Structure that Reflect Changes in Mathematical Thinking…… 130 Debate on the Ratio System Versus the Line System…………………….. 131 On the Field of Analytic Trigonometry…………………………………… 140 Summary…………………………………………………………………... 145 Chapter VI: Turning Trigonometry on its Head…………………………………… 146 A Note on Terminology…………………………………………………… 146 Late Nineteenth Century Teaching of Trigonometry……………………... 148 American Textbooks……………………………………………………… 150 Final Exams in Trigonometry……………………………………………... 168 German Influence in Mathematics Education…………………………….. 172 Trigonometric Definitions Change Radically……………………………... 173 Pedagogy Develops Further……………………………………………….. 176 Changes in the Content of Trigonometry…………………………………. 180 Summary…………………………………………………………………... 187 Chapter VII: Conclusion and Recommendations………………………………….. 188 Research Questions Answered……………………………………………. 189 A Consideration of the Reasons for the Changes…………………………. 196 Limitations of the Study…………………………………………………... 197 Recommendations for Further Study……………………………………… 199 Final Remarks……………………………………………………………... 200 References………………………………………………………………………….. 202 Appendix A: Late Nineteenth Century Textbooks………………………………… 208 ii List of Charts, Graphs, and Illustrations Figure 2.1……...........12 Figure 2.2…………...12 Figure 2.3……………35 Figure 2.4……………39 Figure 3.1……………64 Figure 3.2……………65 Figure 4.1……………69 Figure 4.2……………70 Figure 4.3……………73 Figure 4.4…………….87 Figure 4.5…………….93 Figure 5.1……………134 Figure 6.1……………150 Figure 6.2……………155 Figure 6.3……………156 Figure 6.4……………160 Figure 6.5……………163 Figure 6.6……………182 Figure A.1…………...207 iii Acknowledgements I would like to thank my adviser, Dr. Alexander P. Karp, for his continued guidance and for never letting me settle for anything less than the best. I would also like to thank Dr. J. Philip Smith for mentoring and encouraging me along the way, and for reading drafts of my chapters and responding with wonderfully helpful comments. I would also like to thank the members of my committee, Dr. Bruce Vogeli, Dr. Erica Walker, Dr. Patrick Gallagher, and Dr. Felicia Moore Mensah for taking time out of their busy lives to read this dissertation and participate in my oral defense. Thank you to all the teachers throughout my life, who have taught me, guided me, encouraged me, and believed in me. I have had so many such teachers that I cannot possibly thank them all individually. Without all of you, I would not be here. I would like to express my deepest thanks to all of my family, for their absolutely unwavering support. My parents, Susan and Richard Cain, have always believed in me, loved me, and supported me in every way possible. My husband, Jacob, and my sons, Michael and John, have sacrificed everything for me, and it is to them that I have dedicated this dissertation. I am grateful every day for their unconditional love and constant companionship. Thank you to my Lord, God, and Savior Jesus Christ, for every good and perfect gift is from above. iv To Jacob, Michael, and John v 1 CHAPTER I: Introduction Need for the Study The history of mathematics education is in the focus of research today, both internationally and within the United States. The most notable work on the history of mathematics education in the United States is a two-volume History of School Mathematics, edited by George M. A. Stanic and Jeremy Kilpatrick, published by the National Council of Teachers of Mathematics (2003). The history of mathematics education was the topic of a study group at the International Congress on Mathematics Education in Copenhagen in 2004, and based on the experience of this study group the International Journal for the History of Mathematics Education was created. In recent years, important contributions to the history of mathematics education in the United States have been made by many researchers. These contributors include Amy Ackerberg- Hastings (2000) Leo Corry (2007),, Eileen Frances Donoghue (2001, 2008), Gloriana Gonzalez and Patricio G. Herbst (2006), Dustin Jones (2008), Jeremy Kilpatrick (1994, 2003), Sharon L. Senk and Denisse R. Thompson (2003), George M. A. Stanic (2003), etc. Understanding this history has implications for how mathematics is taught today (Cajori, 1890; Coxford and Jones, 1970; Butts, 1971). Furthermore, ―we, as mathematics 2 educators, need a record of our history not simply to serve as a partial guide to present actions but to better understand who we are‖ (Stanic and Kilpatrick, 2003, p. 13). Currently, there is concern about the state of trigonometry instruction. Current studies on trigonometry instruction include Fi, 2003; McMullin, 2003; Weber, 2005; Thompson, 2007; Bressoud, 2010, etc. A better understanding of the history of trigonometry education will aid researchers
Recommended publications
  • A Genetic Context for Understanding the Trigonometric Functions Danny Otero Xavier University, [email protected]
    Ursinus College Digital Commons @ Ursinus College Transforming Instruction in Undergraduate Pre-calculus and Trigonometry Mathematics via Primary Historical Sources (TRIUMPHS) Spring 3-2017 A Genetic Context for Understanding the Trigonometric Functions Danny Otero Xavier University, [email protected] Follow this and additional works at: https://digitalcommons.ursinus.edu/triumphs_precalc Part of the Curriculum and Instruction Commons, Educational Methods Commons, Higher Education Commons, and the Science and Mathematics Education Commons Click here to let us know how access to this document benefits oy u. Recommended Citation Otero, Danny, "A Genetic Context for Understanding the Trigonometric Functions" (2017). Pre-calculus and Trigonometry. 1. https://digitalcommons.ursinus.edu/triumphs_precalc/1 This Course Materials is brought to you for free and open access by the Transforming Instruction in Undergraduate Mathematics via Primary Historical Sources (TRIUMPHS) at Digital Commons @ Ursinus College. It has been accepted for inclusion in Pre-calculus and Trigonometry by an authorized administrator of Digital Commons @ Ursinus College. For more information, please contact [email protected]. A Genetic Context for Understanding the Trigonometric Functions Daniel E. Otero∗ July 22, 2019 Trigonometry is concerned with the measurements of angles about a central point (or of arcs of circles centered at that point) and quantities, geometrical and otherwise, that depend on the sizes of such angles (or the lengths of the corresponding arcs). It is one of those subjects that has become a standard part of the toolbox of every scientist and applied mathematician. It is the goal of this project to impart to students some of the story of where and how its central ideas first emerged, in an attempt to provide context for a modern study of this mathematical theory.
    [Show full text]
  • Refresher Course Content
    Calculus I Refresher Course Content 4. Exponential and Logarithmic Functions Section 4.1: Exponential Functions Section 4.2: Logarithmic Functions Section 4.3: Properties of Logarithms Section 4.4: Exponential and Logarithmic Equations Section 4.5: Exponential Growth and Decay; Modeling Data 5. Trigonometric Functions Section 5.1: Angles and Radian Measure Section 5.2: Right Triangle Trigonometry Section 5.3: Trigonometric Functions of Any Angle Section 5.4: Trigonometric Functions of Real Numbers; Periodic Functions Section 5.5: Graphs of Sine and Cosine Functions Section 5.6: Graphs of Other Trigonometric Functions Section 5.7: Inverse Trigonometric Functions Section 5.8: Applications of Trigonometric Functions 6. Analytic Trigonometry Section 6.1: Verifying Trigonometric Identities Section 6.2: Sum and Difference Formulas Section 6.3: Double-Angle, Power-Reducing, and Half-Angle Formulas Section 6.4: Product-to-Sum and Sum-to-Product Formulas Section 6.5: Trigonometric Equations 7. Additional Topics in Trigonometry Section 7.1: The Law of Sines Section 7.2: The Law of Cosines Section 7.3: Polar Coordinates Section 7.4: Graphs of Polar Equations Section 7.5: Complex Numbers in Polar Form; DeMoivre’s Theorem Section 7.6: Vectors Section 7.7: The Dot Product 8. Systems of Equations and Inequalities (partially included) Section 8.1: Systems of Linear Equations in Two Variables Section 8.2: Systems of Linear Equations in Three Variables Section 8.3: Partial Fractions Section 8.4: Systems of Nonlinear Equations in Two Variables Section 8.5: Systems of Inequalities Section 8.6: Linear Programming 10. Conic Sections and Analytic Geometry (partially included) Section 10.1: The Ellipse Section 10.2: The Hyperbola Section 10.3: The Parabola Section 10.4: Rotation of Axes Section 10.5: Parametric Equations Section 10.6: Conic Sections in Polar Coordinates 11.
    [Show full text]
  • International Journal for Scientific Research & Development| Vol. 5, Issue 12, 2018 | ISSN (Online): 2321-0613
    IJSRD - International Journal for Scientific Research & Development| Vol. 5, Issue 12, 2018 | ISSN (online): 2321-0613 A Case Study on Applications of Trigonometry in Oceanography Suvitha M.1 Kalaivani M.2 1,2Student 1,2Department of Mathematics 1,2Sri Krishna Arts and Science College, Coimbatore, Tamil Nadu, India Abstract— This article introduces a trigonometric field that bisected to create two right-angle triangles, most problems extends in the field of real numbers adding two elements: sin can be reduced to calculations on right-angle triangles. Thus and cos satisfying an axiom sin²+cos²=1.It is shown that the majority of applications relate to right-angle triangles. assigning meaningful names to particular elements to the One exception to this is spherical trigonometry, the study of field, All know trigonometric identities may be introduced triangles on spheres, surfaces of constant positive curvature, and proved. The main objective of this study is about in elliptic geometry (a fundamental part of astronomy and oceanography how the oceanographers guide everyone with navigation). Trigonometry on surfaces of negative curvature the awareness of the Tsunami waves and protect the marine is part of hyperbolic geometry. animals hitting the ships and cliffs. Key words: Trigonometric Identities, Trigonometric Ratios, II. HISTORY OF TRIGONOMETRY Trigonometric Functions I. INTRODUCTION A. Trigonometry Fig. 2: Hipparchus, credited with compiling the first trigonometric, is known as "the father of trigonometry". A thick ring-like shell object found at the Indus Fig. 1: Valley Civilization site of Lothal, with four slits each in two All of the trigonometric functions of an angle θ can be margins served as a compass to measure angles on plane constructed geometrically in terms of a unit circle centered at surfaces or in the horizon in multiples of 40degrees,upto 360 O.
    [Show full text]
  • Algebra/Geometry/Trigonometry App Samples
    Algebra/Geometry/Trigonometry App Samples Holt McDougal Algebra 1 HMH Fuse: Algebra 1- HMH Fuse is the first core K-12 education solution developed exclusively for the iPad. The portability of a complete classroom course on an iPad enables students to learn in the classroom, on the bus, or at home—anytime, anywhere—with engaging content that provides an individually-tailored learning experience. Students and educators using HMH Fuse: will benefit from: •Instructional videos that teach or re-teach all key concepts •Math Motion is a step-by-step interactive demonstration that displays the process to solve complex equations •Homework Help provides at-home support for intricate problems by providing hints for each step in the solution •Vocabulary support throughout with links to a complete glossary that includes audio definitions •Tips, hints, and links that enable students to acquire the help they need to understand the lessons every step of the way •Quizzes that assess student’s skills before they begin a concept and at strategic points throughout the chapters. Instant, automatic grading of quizzes lets students know exactly how they have performed •Immediate assessment results sent to teachers so they can better differentiate instruction. Sample- Cost is Free, Complete App price- $59.99 Holt McDougal HMH Fuse: Geometry- Following our popular HMH Fuse: Algebra 1 app, HMH Fuse: Geometry is the newest offering in the HMH Fuse series. HMH Fuse: Geometry will allow you a sneak peek at the future of mobile geometry curriculum and includes a FREE sample chapter. HMH Fuse is the first core K-12 education solution developed exclusively for the iPad.
    [Show full text]
  • Trigonometric Functions
    Trigonometric Functions This worksheet covers the basic characteristics of the sine, cosine, tangent, cotangent, secant, and cosecant trigonometric functions. Sine Function: f(x) = sin (x) • Graph • Domain: all real numbers • Range: [-1 , 1] • Period = 2π • x intercepts: x = kπ , where k is an integer. • y intercepts: y = 0 • Maximum points: (π/2 + 2kπ, 1), where k is an integer. • Minimum points: (3π/2 + 2kπ, -1), where k is an integer. • Symmetry: since sin (–x) = –sin (x) then sin(x) is an odd function and its graph is symmetric with respect to the origin (0, 0). • Intervals of increase/decrease: over one period and from 0 to 2π, sin (x) is increasing on the intervals (0, π/2) and (3π/2 , 2π), and decreasing on the interval (π/2 , 3π/2). Tutoring and Learning Centre, George Brown College 2014 www.georgebrown.ca/tlc Trigonometric Functions Cosine Function: f(x) = cos (x) • Graph • Domain: all real numbers • Range: [–1 , 1] • Period = 2π • x intercepts: x = π/2 + k π , where k is an integer. • y intercepts: y = 1 • Maximum points: (2 k π , 1) , where k is an integer. • Minimum points: (π + 2 k π , –1) , where k is an integer. • Symmetry: since cos(–x) = cos(x) then cos (x) is an even function and its graph is symmetric with respect to the y axis. • Intervals of increase/decrease: over one period and from 0 to 2π, cos (x) is decreasing on (0 , π) increasing on (π , 2π). Tutoring and Learning Centre, George Brown College 2014 www.georgebrown.ca/tlc Trigonometric Functions Tangent Function : f(x) = tan (x) • Graph • Domain: all real numbers except π/2 + k π, k is an integer.
    [Show full text]
  • Elementary Functions: Towards Automatically Generated, Efficient
    Elementary functions : towards automatically generated, efficient, and vectorizable implementations Hugues De Lassus Saint-Genies To cite this version: Hugues De Lassus Saint-Genies. Elementary functions : towards automatically generated, efficient, and vectorizable implementations. Other [cs.OH]. Université de Perpignan, 2018. English. NNT : 2018PERP0010. tel-01841424 HAL Id: tel-01841424 https://tel.archives-ouvertes.fr/tel-01841424 Submitted on 17 Jul 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Délivré par l’Université de Perpignan Via Domitia Préparée au sein de l’école doctorale 305 – Énergie et Environnement Et de l’unité de recherche DALI – LIRMM – CNRS UMR 5506 Spécialité: Informatique Présentée par Hugues de Lassus Saint-Geniès [email protected] Elementary functions: towards automatically generated, efficient, and vectorizable implementations Version soumise aux rapporteurs. Jury composé de : M. Florent de Dinechin Pr. INSA Lyon Rapporteur Mme Fabienne Jézéquel MC, HDR UParis 2 Rapporteur M. Marc Daumas Pr. UPVD Examinateur M. Lionel Lacassagne Pr. UParis 6 Examinateur M. Daniel Menard Pr. INSA Rennes Examinateur M. Éric Petit Ph.D. Intel Examinateur M. David Defour MC, HDR UPVD Directeur M. Guillaume Revy MC UPVD Codirecteur À la mémoire de ma grand-mère Françoise Lapergue et de Jos Perrot, marin-pêcheur bigouden.
    [Show full text]
  • Two Editions of Ibn Al-Haytham's Completion of the Conics
    Historia Mathematica 29 (2002), 247–265 doi:10.1006/hmat.2002.2352 Two Editions of Ibn al-Haytham’s Completion of the Conics View metadata, citation and similar papers at core.ac.uk brought to you by CORE Jan P. Hogendijk provided by Elsevier - Publisher Connector Mathematics Department, University of Utrecht, P.O. Box 80.010, 3508 TA Utrecht, Netherlands E-mail: [email protected] The lost Book VIII of the Conics of Apollonius of Perga (ca. 200 B.C.) was reconstructed by the Islamic mathematician Ibn al-Haytham (ca. A.D. 965–1041) in his Completion of the Conics. The Arabic text of this reconstruction with English translation and commentary was published as J. P. Hogendijk, Ibn al-Haytham’s Completion of the Conics (New York: Springer-Verlag, 1985). In a new Arabic edition with French translation and commentary (R. Rashed, Les mathematiques´ infinitesimales´ du IXe au XIe siecle.´ Vol. 3., London: Al-Furqan Foundation, 2000), it was claimed that my edition is faulty. In this paper the similarities and differences between the two editions, translations, and commentaries are discussed, with due consideration for readers who do not know Arabic. The facts will speak for themselves. C 2002 Elsevier Science (USA) C 2002 Elsevier Science (USA) C 2002 Elsevier Science (USA) 247 0315-0860/02 $35.00 C 2002 Elsevier Science (USA) All rights reserved. 248 JAN P. HOGENDIJK HMAT 29 AMS subject classifications: 01A20, 01A30. Key Words: Ibn al-Haytham; conic sections; multiple editions; Rashed. 1. INTRODUCTION The Conics of Apollonius of Perga (ca. 200 B.C.) is one of the fundamental texts of ancient Greek geometry.
    [Show full text]
  • History of Mathematics in Mathematics Education. Recent Developments Kathy Clark, Tinne Kjeldsen, Sebastian Schorcht, Constantinos Tzanakis, Xiaoqin Wang
    History of mathematics in mathematics education. Recent developments Kathy Clark, Tinne Kjeldsen, Sebastian Schorcht, Constantinos Tzanakis, Xiaoqin Wang To cite this version: Kathy Clark, Tinne Kjeldsen, Sebastian Schorcht, Constantinos Tzanakis, Xiaoqin Wang. History of mathematics in mathematics education. Recent developments. History and Pedagogy of Mathematics, Jul 2016, Montpellier, France. hal-01349230 HAL Id: hal-01349230 https://hal.archives-ouvertes.fr/hal-01349230 Submitted on 27 Jul 2016 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. HISTORY OF MATHEMATICS IN MATHEMATICS EDUCATION Recent developments Kathleen CLARK, Tinne Hoff KJELDSEN, Sebastian SCHORCHT, Constantinos TZANAKIS, Xiaoqin WANG School of Teacher Education, Florida State University, Tallahassee, FL 32306-4459, USA [email protected] Department of Mathematical Sciences, University of Copenhagen, Denmark [email protected] Justus Liebig University Giessen, Germany [email protected] Department of Education, University of Crete, Rethymnon 74100, Greece [email protected] Department of Mathematics, East China Normal University, China [email protected] ABSTRACT This is a survey on the recent developments (since 2000) concerning research on the relations between History and Pedagogy of Mathematics (the HPM domain). Section 1 explains the rationale of the study and formulates the key issues.
    [Show full text]
  • Plane Trigonometry - Lecture 16 Section 3.2: the Law of Cosines
    Plane Trigonometry - Lecture 16 Section 3.2: The Law of Cosines Summary: http://www.math.ksu.edu/~gerald/math150/sum16.pdf Course page: http://www.math.ksu.edu/~gerald/math150/ Gerald Hoehn April 1, 2019 Law of cosines Theorem Let ∆ABC any triangle, then c2 = a2 + b2 − 2ab cos γ b2 = a2 + c2 − 2ac cos β a2 = b2 + c2 − 2bc cos α We may reformulate the statement also in word form. Theorem In any triangle, the square of the length of a side equals the sum of the squares of the length of the other two sides minus twice the product of the length of the other two sides and the cosine of the angle between them. Solving Triangles For solving triangles ∆ABC one needs at least three of the six quantities a, b, and c and α, β, γ. One distinguishes six essential different cases forming three classes: I AAA case: Three angles given. I AAS case: Two angles and a side opposite one of them given. I ASA case: Two angles and the side between them given. I SSA case: Two sides and an angle opposite one of them given. I SAS case: Two sides and the angle between them given. I SSS case: Three sides given. The case AAA cannot be solved. The cases AAS, ASA and SSA are solved by using the law of sines. The cases SAS, SSS are solved by using the law of cosines. Solving Triangles: the SAS case For the SAS case a unique solution always exists. Three steps: 1. Use the law of cosines to determine the length of the third side opposite to the given angle.
    [Show full text]
  • Trigonometry Cram Sheet
    Trigonometry Cram Sheet August 3, 2016 Contents 6.2 Identities . 8 1 Definition 2 7 Relationships Between Sides and Angles 9 1.1 Extensions to Angles > 90◦ . 2 7.1 Law of Sines . 9 1.2 The Unit Circle . 2 7.2 Law of Cosines . 9 1.3 Degrees and Radians . 2 7.3 Law of Tangents . 9 1.4 Signs and Variations . 2 7.4 Law of Cotangents . 9 7.5 Mollweide’s Formula . 9 2 Properties and General Forms 3 7.6 Stewart’s Theorem . 9 2.1 Properties . 3 7.7 Angles in Terms of Sides . 9 2.1.1 sin x ................... 3 2.1.2 cos x ................... 3 8 Solving Triangles 10 2.1.3 tan x ................... 3 8.1 AAS/ASA Triangle . 10 2.1.4 csc x ................... 3 8.2 SAS Triangle . 10 2.1.5 sec x ................... 3 8.3 SSS Triangle . 10 2.1.6 cot x ................... 3 8.4 SSA Triangle . 11 2.2 General Forms of Trigonometric Functions . 3 8.5 Right Triangle . 11 3 Identities 4 9 Polar Coordinates 11 3.1 Basic Identities . 4 9.1 Properties . 11 3.2 Sum and Difference . 4 9.2 Coordinate Transformation . 11 3.3 Double Angle . 4 3.4 Half Angle . 4 10 Special Polar Graphs 11 3.5 Multiple Angle . 4 10.1 Limaçon of Pascal . 12 3.6 Power Reduction . 5 10.2 Rose . 13 3.7 Product to Sum . 5 10.3 Spiral of Archimedes . 13 3.8 Sum to Product . 5 10.4 Lemniscate of Bernoulli . 13 3.9 Linear Combinations .
    [Show full text]
  • By the Persian Mathematician and Engineer Abubakr
    1 2 The millennium old hydrogeology textbook “The Extraction of Hidden Waters” by the Persian 3 mathematician and engineer Abubakr Mohammad Karaji (c. 953 – c. 1029) 4 5 Behzad Ataie-Ashtiania,b, Craig T. Simmonsa 6 7 a National Centre for Groundwater Research and Training and College of Science & Engineering, 8 Flinders University, Adelaide, South Australia, Australia 9 b Department of Civil Engineering, Sharif University of Technology, Tehran, Iran, 10 [email protected] (B. Ataie-Ashtiani) 11 [email protected] (C. T. Simmons) 12 13 14 15 Hydrology and Earth System Sciences (HESS) 16 Special issue ‘History of Hydrology’ 17 18 Guest Editors: Okke Batelaan, Keith Beven, Chantal Gascuel-Odoux, Laurent Pfister, and Roberto Ranzi 19 20 1 21 22 Abstract 23 We revisit and shed light on the millennium old hydrogeology textbook “The Extraction of Hidden Waters” by the 24 Persian mathematician and engineer Karaji. Despite the nature of the understanding and conceptualization of the 25 world by the people of that time, ground-breaking ideas and descriptions of hydrological and hydrogeological 26 perceptions such as components of hydrological cycle, groundwater quality and even driving factors for 27 groundwater flow were presented in the book. Although some of these ideas may have been presented elsewhere, 28 to the best of our knowledge, this is the first time that a whole book was focused on different aspects of hydrology 29 and hydrogeology. More importantly, we are impressed that the book is composed in a way that covered all aspects 30 that are related to an engineering project including technical and construction issues, guidelines for maintenance, 31 and final delivery of the project when the development and construction was over.
    [Show full text]
  • Chapter 6 Additional Topics in Trigonometry
    1111572836_0600.qxd 9/29/10 1:43 PM Page 403 Additional Topics 6 in Trigonometry 6.1 Law of Sines 6.2 Law of Cosines 6.3 Vectors in the Plane 6.4 Vectors and Dot Products 6.5 Trigonometric Form of a Complex Number Section 6.3, Example 10 Direction of an Airplane Andresr 2010/used under license from Shutterstock.com 403 Copyright 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 1111572836_0601.qxd 10/12/10 4:10 PM Page 404 404 Chapter 6 Additional Topics in Trigonometry 6.1 Law of Sines Introduction What you should learn ● Use the Law of Sines to solve In Chapter 4, you looked at techniques for solving right triangles. In this section and the oblique triangles (AAS or ASA). next, you will solve oblique triangles—triangles that have no right angles. As standard ● Use the Law of Sines to solve notation, the angles of a triangle are labeled oblique triangles (SSA). A, , and CB ● Find areas of oblique triangles and use the Law of Sines to and their opposite sides are labeled model and solve real-life a, , and cb problems. as shown in Figure 6.1. Why you should learn it You can use the Law of Sines to solve C real-life problems involving oblique triangles.
    [Show full text]