Chapter 3 Cartesian Coordinate System

Total Page:16

File Type:pdf, Size:1020Kb

Chapter 3 Cartesian Coordinate System Physical constant From Wikipedia, the free encyclopedia Contents 1 Amplitude 1 1.1 Definitions of the term ......................................... 1 1.1.1 Peak-to-peak amplitude .................................... 1 1.1.2 Peak amplitude ........................................ 1 1.1.3 Semi-amplitude ........................................ 1 1.1.4 Root mean square amplitude ................................. 1 1.1.5 Ambiguity ........................................... 2 1.1.6 Pulse amplitude ........................................ 3 1.2 Formal representation ......................................... 3 1.3 Units .................................................. 3 1.4 Waveform and envelope ........................................ 3 1.5 Sinusoids ............................................... 4 1.6 See also ................................................ 4 1.7 Notes ................................................. 4 2 Arithmetic progression 5 2.1 Sum .................................................. 5 2.1.1 Derivation .......................................... 6 2.2 Product ................................................ 6 2.3 Standard deviation ........................................... 7 2.4 Intersections .............................................. 7 2.5 Formulas at a Glance ......................................... 7 2.6 See also ................................................ 8 2.7 References .............................................. 8 2.8 External links ............................................. 8 3 Cartesian coordinate system 9 3.1 History ................................................. 11 3.2 Description .............................................. 11 3.2.1 One dimension ........................................ 11 3.2.2 Two dimensions ........................................ 11 3.2.3 Three dimensions ....................................... 12 3.2.4 Higher dimensions ...................................... 13 i ii CONTENTS 3.2.5 Generalizations ........................................ 13 3.3 Notations and conventions ....................................... 14 3.3.1 Quadrants and octants ..................................... 14 3.4 Cartesian formulae for the plane .................................... 14 3.4.1 Distance between two points ................................. 14 3.4.2 Euclidean transformations ................................... 15 3.5 Orientation and handedness ...................................... 18 3.5.1 In two dimensions ....................................... 18 3.5.2 In three dimensions ...................................... 19 3.6 Representing a vector in the standard basis .............................. 21 3.7 Applications .............................................. 21 3.8 See also ................................................ 22 3.9 Notes ................................................. 22 3.10 References ............................................... 22 3.11 Sources ................................................ 22 3.12 Further reading ............................................ 23 3.13 External links ............................................. 23 4 Diophantine equation 24 4.1 Examples ............................................... 25 4.2 Linear Diophantine equations ..................................... 25 4.2.1 One equation ......................................... 25 4.2.2 Chinese remainder theorem .................................. 25 4.2.3 System of linear Diophantine equations ............................ 25 4.3 Diophantine analysis .......................................... 26 4.3.1 Typical questions ....................................... 26 4.3.2 Typical problem ....................................... 27 4.3.3 17th and 18th centuries .................................... 27 4.3.4 Hilbert’s tenth problem .................................... 27 4.3.5 Diophantine geometry .................................... 27 4.3.6 Modern research ....................................... 27 4.3.7 Infinite Diophantine equations ................................ 28 4.4 Exponential Diophantine equations .................................. 28 4.5 Notes ................................................. 28 4.6 References ............................................... 29 4.7 Further reading ............................................ 29 4.8 External links ............................................. 29 5 Equation 30 5.1 Introduction .............................................. 30 5.1.1 Parameters and unknowns .................................. 30 5.1.2 Analogous illustration ..................................... 31 CONTENTS iii 5.1.3 Identities ........................................... 32 5.2 Properties ............................................... 33 5.3 Algebra ................................................ 34 5.3.1 Polynomial equations ..................................... 34 5.3.2 Systems of linear equations .................................. 34 5.4 Geometry ............................................... 36 5.4.1 Analytic geometry ...................................... 36 5.4.2 Cartesian equations ...................................... 36 5.4.3 Parametric equations ..................................... 37 5.5 Number theory ............................................ 38 5.5.1 Diophantine equations .................................... 38 5.5.2 Algebraic and transcendental numbers ............................ 38 5.5.3 Algebraic geometry ...................................... 38 5.6 Differential equations ......................................... 38 5.6.1 Ordinary differential equations ................................ 39 5.6.2 Partial differential equations ................................. 39 5.7 Types of equations .......................................... 39 5.8 See also ................................................ 40 5.9 References ............................................... 40 5.10 External links ............................................. 41 6 Geometric progression 42 6.1 Elementary properties ......................................... 43 6.2 Geometric series ............................................ 44 6.2.1 Derivation ........................................... 44 6.2.2 Related formulas ....................................... 44 6.2.3 Infinite geometric series .................................... 45 6.2.4 Complex numbers ....................................... 47 6.3 Product ................................................ 47 6.4 Relationship to geometry and Euclid’s work .............................. 48 6.5 See also ................................................ 48 6.6 References ............................................... 49 6.7 External links ............................................. 49 7 Geometric series 50 7.1 Common ratio ............................................. 51 7.2 Sum .................................................. 52 7.2.1 Example ............................................ 52 7.2.2 Formula ............................................ 53 7.2.3 Proof of convergence ..................................... 53 7.2.4 Generalized formula ..................................... 54 7.3 Applications .............................................. 55 iv CONTENTS 7.3.1 Repeating decimals ...................................... 55 7.3.2 Archimedes’ quadrature of the parabola ........................... 55 7.3.3 Fractal geometry ....................................... 56 7.3.4 Zeno’s paradoxes ....................................... 57 7.3.5 Euclid ............................................. 58 7.3.6 Economics .......................................... 58 7.3.7 Geometric power series .................................... 58 7.4 See also ................................................ 59 7.4.1 Specific geometric series ................................... 59 7.5 References ............................................... 60 7.5.1 History and philosophy .................................... 60 7.5.2 Economics .......................................... 60 7.5.3 Biology ............................................ 61 7.5.4 Computer science ....................................... 61 7.6 External links ............................................. 61 8 Physical constant 62 8.1 Dimensional and dimensionless physical constants .......................... 62 8.2 How constant are the physical constants? ............................... 63 8.3 Anthropic principle .......................................... 63 8.4 Table of universal constants ...................................... 64 8.5 Table of electromagnetic constants .................................. 64 8.6 Table of atomic and nuclear constants ................................. 64 8.7 Table of physico-chemical constants .................................. 64 8.8 Table of adopted values ........................................ 64 8.9 Natural units .............................................. 64 8.10 See also ................................................ 64 8.11 References ............................................... 64 8.12 External links ............................................. 65 9 Scale factor 66 9.1 See also ................................................ 66 10 Sequence 67 10.1 Examples and notation ........................................ 68 10.1.1 Important examples ...................................... 68 10.1.2 Indexing ............................................ 69 10.1.3 Specifying a sequence by recursion ............................. 70 10.2 Formal definition and basic
Recommended publications
  • Hasse Principles for Higher-Dimensional Fields 3
    Annals of Mathematics 183 (2016), 1{71 http://dx.doi.org/10.4007/annals.2016.183.1.1 Hasse principles for higher-dimensional fields By Uwe Jannsen dedicated to J¨urgen Neukirch Abstract For rather general excellent schemes X, K. Kato defined complexes of Gersten-Bloch-Ogus type involving the Galois cohomology groups of all residue fields of X. For arithmetically interesting schemes, he developed a fascinating web of conjectures on some of these complexes, which generalize the classical Hasse principle for Brauer groups over global fields, and proved these conjectures for low dimensions. We prove Kato's conjecture over number fields in any dimension. This gives a cohomological Hasse principle for function fields F over a number field K, involving the corresponding function fields Fv over the completions Kv of K. For global function fields K we prove the part on injectivity for coefficients invertible in K. Assuming resolution of singularities, we prove a similar conjecture of Kato over finite fields, and a generalization to arbitrary finitely generated fields. Contents 0. Introduction1 1. First reductions and a Hasse principle for global fields7 2. Injectivity of the global-local map for coefficients invertible in K 16 3. A crucial exact sequence, and a Hasse principle for unramified cohomology 26 4. A Hasse principle for Bloch-Ogus-Kato complexes 40 5. Weight complexes and weight cohomology 52 References 67 0. Introduction In this paper we prove some conjectures of K. Kato [Kat86] which were formulated to generalize the classical exact sequence of Brauer groups for a global field K, L (0.1) 0 −! Br(K) −! Br(Kv) −! Q=Z −! 0; v c 2016 Department of Mathematics, Princeton University.
    [Show full text]
  • Conics Over Function Fields and the Artin-Tate Conjecture José Felipe
    Conics over function fields and the Artin-Tate conjecture Jos´eFelipe Voloch Abstract: We prove that the Hasse principle for conics over function fields is a simple consequence of a provable case of the Artin-Tate conjecture for surfaces over finite fields. Hasse proved that a conic over a global field has a rational point if and only if it has points over all completions of the global field, an instance of the so-called local-global or Hasse principle. The case of the rational numbers is an old result of Legendre, who gave an elementary proof and a similar proof can be given in the case of rational functions over a finite field. Hasse’s proof, on the other hand, is a consequence of a more general result in Class Field Theory, the Hasse norm theorem. One purpose of this paper is to give a new proof of the local-global principle for conics over function fields, as a relatively simple consequence of a provable case of the Artin-Tate conjecture for surfaces over finite fields. This proof might be more complicated overall, once the work on the Artin-Tate conjecture is factored in, but it might be worthwhile recording since it suggests a new approach to local-global principles which might work in other contexts, such as number fields or higher dimensions. We also deduce from the Artin-Tate conjecture, together with a recent result [LLR] on Brauer groups, the Hilbert reciprocity law. We also do a careful study of conic bundles over curves over finite fields which might have independent interest.
    [Show full text]
  • Counterexamples to the Hasse Principle
    COUNTEREXAMPLES TO THE HASSE PRINCIPLE W. AITKEN AND F. LEMMERMEYER Abstract. This article explains the Hasse principle and gives a self-contained development of certain counterexamples to this principle. The counterexam- ples considered are similar to the earliest counterexample discovered by Lind and Reichardt. This type of counterexample is important in the theory of elliptic curves: today they are interpreted as nontrivial elements in Tate– Shafarevich groups. 1. Introduction In this article we develop counterexamplestotheHasseprincipleusingonlytech- niques from undergraduate number theory and algebra. By keeping the technical prerequisites to a minimum, we hope to provide a path for nonspecialists to this interesting area of number theory. The counterexamples considered here extend the classical counterexample of Lind and Reichardt. As discussed in an appendix, such counterexamples are important in the theory of elliptic curves, and today are interpreted as nontrivial elements in Tate–Shafarevich groups. 2. Background The problem of determining if the Diophantine equation aX2 + bY 2 + cZ2 =0 (1) has nontrivial solutions with values in Z has played a prominent role in the history of number theory. We assume that a, b, and c are nonzero integers and, using a simple argument, we reduce to the case where the product abc is square-free. Lagrange (1768) solved the problem by giving a descent procedure which determines in a finite number of steps whether or not (1) has a nontrivial Z-solution, but Legendre (1788) gave the definitive solution. Legendre proved that the following conditions, known by Euler to be necessary, are sufficient for the existence of a nontrivial Z- solution: (i) a, b,andc do not all have the same sign, and (ii) ab is a square modulo c , ca is a square modulo b ,and bc is a square modulo− a .
    [Show full text]
  • Algebraic Tori — Thirty Years After
    ALGEBRAIC TORI | THIRTY YEARS AFTER BORIS KUNYAVSKI˘I To my teacher Valentin Evgenyevich Voskresenski˘ı, with gratitude and admiration This article is an expanded version of my talk given at the Interna- tional Conference \Algebra and Number Theory" dedicated to the 80th anniversary of V. E. Voskresenski˘ı, which was held at the Samara State University in May 2007. The goal is to give an overview of results of V. E. Voskresenski˘ı on arithmetic and birational properties of algebraic tori which culminated in his monograph [Vo77] published 30 years ago. I shall try to put these results and ideas into somehow broader context and also to give a brief digest of the relevant activity related to the period after the English version of the monograph [Vo98] appeared. 1. Rationality and nonrationality problems A classical problem, going back to Pythagorean triples, of describing the set of solutions of a given system of polynomial equations by ratio- nal functions in a certain number of parameters (rationality problem) has been an attraction for many generations. Although a lot of various techniques have been used, one can notice that after all, to establish rationality, one usually has to exhibit some explicit parameterization such as that obtained by stereographic projection in the Pythagoras problem. The situation is drastically different if one wants to estab- lish non-existence of such a parameterization (nonrationality problem): here one usually has to use some known (or even invent some new) bi- rational invariant allowing one to detect nonrationality by comparing its value for the object under consideration with some \standard" one known to be zero; if the computation gives a nonzero value, we are done.
    [Show full text]
  • Old-Fashioned Relativity & Relativistic Space-Time Coordinates
    Relativistic Coordinates-Classic Approach 4.A.1 Appendix 4.A Relativistic Space-time Coordinates The nature of space-time coordinate transformation will be described here using a fictional spaceship traveling at half the speed of light past two lighthouses. In Fig. 4.A.1 the ship is just passing the Main Lighthouse as it blinks in response to a signal from the North lighthouse located at one light second (about 186,000 miles or EXACTLY 299,792,458 meters) above Main. (Such exactitude is the result of 1970-80 work by Ken Evenson's lab at NIST (National Institute of Standards and Technology in Boulder) and adopted by International Standards Committee in 1984.) Now the speed of light c is a constant by civil law as well as physical law! This came about because time and frequency measurement became so much more precise than distance measurement that it was decided to define the meter in terms of c. Fig. 4.A.1 Ship passing Main Lighthouse as it blinks at t=0. This arrangement is a simplified model for a 1Hz laser resonator. The two lighthouses use each other to maintain a strict one-second time period between blinks. And, strict it must be to do relativistic timing. (Even stricter than NIST is the universal agency BIGANN or Bureau of Intergalactic Aids to Navigation at Night.) The simulations shown here are done using RelativIt. Relativistic Coordinates-Classic Approach 4.A.2 Fig. 4.A.2 Main and North Lighthouses blink each other at precisely t=1. At p recisel y t=1 sec.
    [Show full text]
  • Cohomological Hasse Principle and Motivic Cohomology for Arithmetic Schemes
    COHOMOLOGICAL HASSE PRINCIPLE AND MOTIVIC COHOMOLOGY FOR ARITHMETIC SCHEMES by MORITZ KERZ and SHUJI SAITO ABSTRACT In 1985 Kazuya Kato formulated a fascinating framework of conjectures which generalizes the Hasse principle for the Brauer group of a global field to the so-called cohomological Hasse principle for an arithmetic scheme X. In this paper we prove the prime-to-characteristic part of the cohomological Hasse principle. We also explain its implications on finiteness of motivic cohomology and special values of zeta functions. CONTENTS Introduction........................................................ 123 1.Homologytheory................................................... 129 2.Log-pairsandconfigurationcomplexes....................................... 135 3.Lefschetzcondition.................................................. 140 4.Pullbackmap(firstconstruction)........................................... 146 5.Pullbackmap(secondconstruction)......................................... 159 6.Maintheorem..................................................... 162 7.Resultwithfinitecoefficients............................................. 166 8.Kato’sconjectures................................................... 169 9.Applicationtocyclemaps............................................... 174 10.Applicationtospecialvaluesofzetafunctions.................................... 176 Acknowledgements..................................................... 178 Appendix A: Galois cohomology with compact support . .............................. 179 References........................................................
    [Show full text]
  • Solving Equations; Patterns, Functions, and Algebra; 8.15A
    Mathematics Enhanced Scope and Sequence – Grade 8 Solving Equations Reporting Category Patterns, Functions, and Algebra Topic Solving equations in one variable Primary SOL 8.15a The student will solve multistep linear equations in one variable with the variable on one and two sides of the equation. Materials • Sets of algebra tiles • Equation-Solving Balance Mat (attached) • Equation-Solving Ordering Cards (attached) • Be the Teacher: Solving Equations activity sheet (attached) • Student whiteboards and markers Vocabulary equation, variable, coefficient, constant (earlier grades) Student/Teacher Actions (what students and teachers should be doing to facilitate learning) 1. Give each student a set of algebra tiles and a copy of the Equation-Solving Balance Mat. Lead students through the steps for using the tiles to model the solutions to the following equations. As you are working through the solution of each equation with the students, point out that you are undoing each operation and keeping the equation balanced by doing the same thing to both sides. Explain why you do this. When students are comfortable with modeling equation solutions with algebra tiles, transition to writing out the solution steps algebraically while still using the tiles. Eventually, progress to only writing out the steps algebraically without using the tiles. • x + 3 = 6 • x − 2 = 5 • 3x = 9 • 2x + 1 = 9 • −x + 4 = 7 • −2x − 1 = 7 • 3(x + 1) = 9 • 2x = x − 5 Continue to allow students to use the tiles whenever they wish as they work to solve equations. 2. Give each student a whiteboard and marker. Provide students with a problem to solve, and as they write each step, have them hold up their whiteboards so you can ensure that they are completing each step correctly and understanding the process.
    [Show full text]
  • Catoni F., Et Al. the Mathematics of Minkowski Space-Time.. With
    Frontiers in Mathematics Advisory Editorial Board Leonid Bunimovich (Georgia Institute of Technology, Atlanta, USA) Benoît Perthame (Ecole Normale Supérieure, Paris, France) Laurent Saloff-Coste (Cornell University, Rhodes Hall, USA) Igor Shparlinski (Macquarie University, New South Wales, Australia) Wolfgang Sprössig (TU Bergakademie, Freiberg, Germany) Cédric Villani (Ecole Normale Supérieure, Lyon, France) Francesco Catoni Dino Boccaletti Roberto Cannata Vincenzo Catoni Enrico Nichelatti Paolo Zampetti The Mathematics of Minkowski Space-Time With an Introduction to Commutative Hypercomplex Numbers Birkhäuser Verlag Basel . Boston . Berlin $XWKRUV )UDQFHVFR&DWRQL LQFHQ]R&DWRQL LDHJOLD LDHJOLD 5RPD 5RPD Italy Italy HPDLOYMQFHQ]R#\DKRRLW Dino Boccaletti 'LSDUWLPHQWRGL0DWHPDWLFD (QULFR1LFKHODWWL QLYHUVLWjGL5RPD²/D6DSLHQ]D³ (1($&5&DVDFFLD 3LD]]DOH$OGR0RUR LD$QJXLOODUHVH 5RPD 5RPD Italy Italy HPDLOERFFDOHWWL#XQLURPDLW HPDLOQLFKHODWWL#FDVDFFLDHQHDLW 5REHUWR&DQQDWD 3DROR=DPSHWWL (1($&5&DVDFFLD (1($&5&DVDFFLD LD$QJXLOODUHVH LD$QJXLOODUHVH 5RPD 5RPD Italy Italy HPDLOFDQQDWD#FDVDFFLDHQHDLW HPDLO]DPSHWWL#FDVDFFLDHQHDLW 0DWKHPDWLFDO6XEMHFW&ODVVL½FDWLRQ*(*4$$ % /LEUDU\RI&RQJUHVV&RQWURO1XPEHU Bibliographic information published by Die Deutsche Bibliothek 'LH'HXWVFKH%LEOLRWKHNOLVWVWKLVSXEOLFDWLRQLQWKH'HXWVFKH1DWLRQDOELEOLRJUD½H GHWDLOHGELEOLRJUDSKLFGDWDLVDYDLODEOHLQWKH,QWHUQHWDWKWWSGQEGGEGH! ,6%1%LUNKlXVHUHUODJ$*%DVHOÀ%RVWRQÀ% HUOLQ 7KLVZRUNLVVXEMHFWWRFRS\ULJKW$OOULJKWVDUHUHVHUYHGZKHWKHUWKHZKROHRUSDUWRIWKH PDWHULDOLVFRQFHUQHGVSHFL½FDOO\WKHULJKWVRIWUDQVODWLRQUHSULQWLQJUHXVHRILOOXVWUD
    [Show full text]
  • Counterexamples to the Local-Global Principle for Non-Singular Plane Curves and a Cubic Analogue of Ankeny-Artin-Chowla-Mordell Conjecture
    COUNTEREXAMPLES TO THE LOCAL-GLOBAL PRINCIPLE FOR NON-SINGULAR PLANE CURVES AND A CUBIC ANALOGUE OF ANKENY-ARTIN-CHOWLA-MORDELL CONJECTURE YOSHINOSUKE HIRAKAWA AND YOSUKE SHIMIZU Abstract. In this article, we introduce a systematic and uniform construction of non- singular plane curves of odd degrees n ≥ 5 which violate the local-global principle. Our construction works unconditionally for n divisible by p2 for some odd prime number p. Moreover, our construction also works for n divisible by some p ≥ 5 which satisfies 1=3 1=3 a conjecture on p-adic properties of the fundamental units of Q(p ) and Q((2p) ). This conjecture is a natural cubic analogue of the classical Ankeny-Artin-Chowla-Mordell 1=2 conjecture for Q(p ) and easily verified numerically. 1. Introduction In the theory of Diophantine equations, the local-global principle for quadratic forms established by Minkowski and Hasse is one of the major culminations (cf. [31, Theorem 8, Ch. IV]). In contrast, there exist many homogeneous forms of higher degrees which violate the local-global principle (i.e., counterexamples to the local-global principle). For example, Selmer [30] found that a non-singular plane cubic curve defined by (1) 3X3 + 4Y 3 = 5Z3 has rational points over R and Qp for every prime number p but not over Q. From eq. (1), we can easily construct reducible (especially singular) counterexamples of higher degrees. After that, Fujiwara [13] found that a non-singular plane quintic curve defined by (2) (X3 + 5Z3)(X2 + XY + Y 2) = 17Z5 violates the local-global principle. More recently, Cohen [9, Corollary 6.4.11] gave several p p p counterexamples of the form x + by + cz = 0 of degree p = 3; 5; 7; 11 with b; c 2 Z, and Nguyen [23, 24] gave recipes for counterexamples of even degrees and more complicated forms.
    [Show full text]
  • Diffman: an Object-Oriented MATLAB Toolbox for Solving Differential Equations on Manifolds
    Applied Numerical Mathematics 39 (2001) 323–347 www.elsevier.com/locate/apnum DiffMan: An object-oriented MATLAB toolbox for solving differential equations on manifolds Kenth Engø a,∗,1, Arne Marthinsen b,2, Hans Z. Munthe-Kaas a,3 a Department of Informatics, University of Bergen, N-5020 Bergen, Norway b Department of Mathematical Sciences, NTNU, N-7491 Trondheim, Norway Abstract We describe an object-oriented MATLAB toolbox for solving differential equations on manifolds. The software reflects recent development within the area of geometric integration. Through the use of elements from differential geometry, in particular Lie groups and homogeneous spaces, coordinate free formulations of numerical integrators are developed. The strict mathematical definitions and results are well suited for implementation in an object- oriented language, and, due to its simplicity, the authors have chosen MATLAB as the working environment. The basic ideas of DiffMan are presented, along with particular examples that illustrate the working of and the theory behind the software package. 2001 IMACS. Published by Elsevier Science B.V. All rights reserved. Keywords: Geometric integration; Numerical integration of ordinary differential equations on manifolds; Numerical analysis; Lie groups; Lie algebras; Homogeneous spaces; Object-oriented programming; MATLAB; Free Lie algebras 1. Introduction DiffMan is an object-oriented MATLAB [24] toolbox designed to solve differential equations evolving on manifolds. The current version of the toolbox addresses primarily the solution of ordinary differential equations. The solution techniques implemented fall into the category of geometric integrators— a very active area of research during the last few years. The essence of geometric integration is to construct numerical methods that respect underlying constraints, for instance, the configuration space * Corresponding author.
    [Show full text]
  • Hyperbolic Geometry
    Flavors of Geometry MSRI Publications Volume 31,1997 Hyperbolic Geometry JAMES W. CANNON, WILLIAM J. FLOYD, RICHARD KENYON, AND WALTER R. PARRY Contents 1. Introduction 59 2. The Origins of Hyperbolic Geometry 60 3. Why Call it Hyperbolic Geometry? 63 4. Understanding the One-Dimensional Case 65 5. Generalizing to Higher Dimensions 67 6. Rudiments of Riemannian Geometry 68 7. Five Models of Hyperbolic Space 69 8. Stereographic Projection 72 9. Geodesics 77 10. Isometries and Distances in the Hyperboloid Model 80 11. The Space at Infinity 84 12. The Geometric Classification of Isometries 84 13. Curious Facts about Hyperbolic Space 86 14. The Sixth Model 95 15. Why Study Hyperbolic Geometry? 98 16. When Does a Manifold Have a Hyperbolic Structure? 103 17. How to Get Analytic Coordinates at Infinity? 106 References 108 Index 110 1. Introduction Hyperbolic geometry was created in the first half of the nineteenth century in the midst of attempts to understand Euclid’s axiomatic basis for geometry. It is one type of non-Euclidean geometry, that is, a geometry that discards one of Euclid’s axioms. Einstein and Minkowski found in non-Euclidean geometry a This work was supported in part by The Geometry Center, University of Minnesota, an STC funded by NSF, DOE, and Minnesota Technology, Inc., by the Mathematical Sciences Research Institute, and by NSF research grants. 59 60 J. W. CANNON, W. J. FLOYD, R. KENYON, AND W. R. PARRY geometric basis for the understanding of physical time and space. In the early part of the twentieth century every serious student of mathematics and physics studied non-Euclidean geometry.
    [Show full text]
  • Teaching Strategies for Improving Algebra Knowledge in Middle and High School Students
    EDUCATOR’S PRACTICE GUIDE A set of recommendations to address challenges in classrooms and schools WHAT WORKS CLEARINGHOUSE™ Teaching Strategies for Improving Algebra Knowledge in Middle and High School Students NCEE 2015-4010 U.S. DEPARTMENT OF EDUCATION About this practice guide The Institute of Education Sciences (IES) publishes practice guides in education to provide edu- cators with the best available evidence and expertise on current challenges in education. The What Works Clearinghouse (WWC) develops practice guides in conjunction with an expert panel, combining the panel’s expertise with the findings of existing rigorous research to produce spe- cific recommendations for addressing these challenges. The WWC and the panel rate the strength of the research evidence supporting each of their recommendations. See Appendix A for a full description of practice guides. The goal of this practice guide is to offer educators specific, evidence-based recommendations that address the challenges of teaching algebra to students in grades 6 through 12. This guide synthesizes the best available research and shares practices that are supported by evidence. It is intended to be practical and easy for teachers to use. The guide includes many examples in each recommendation to demonstrate the concepts discussed. Practice guides published by IES are available on the What Works Clearinghouse website at http://whatworks.ed.gov. How to use this guide This guide provides educators with instructional recommendations that can be implemented in conjunction with existing standards or curricula and does not recommend a particular curriculum. Teachers can use the guide when planning instruction to prepare students for future mathemat- ics and post-secondary success.
    [Show full text]