A Smoother Pebble: Mathematical Explorations

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Oxford University Press, Oct 30, 2003 - Mathematics - 280 pages
This book takes a novel look at the topics of school mathematics--arithmetic, geometry, algebra, and calculus. In this stroll on the mathematical seashore we hope to find, quoting Newton, "...a smoother pebble or a prettier shell than ordinary..." This book assembles a collection of mathematical pebbles that are important as well as beautiful.

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Contents

Graphical Solutions
129
Quadratic Equations
130
Secrecy Jealousy Rivalry Pugnacity and Guile
135
Solving a cubic equation
138
Symmetry Without Fear
142
Symmetries of a Square
145
The Group Axioms
148
Isometrics of the Plane
150

Magnitudes Ratio and Proportion
22
Method 1 proportion according to Eudoxus
24
Method 2 Attributed to Theaetetus
26
The Music of the Ratios
33
Acoustics
35
The rotating circle
36
Waveforms and spectra
39
Psychoacoustics
44
Consonance versus dissonance
45
Critical bandwidth
46
Intervals Scales and Tuning
49
Approximating m octaves with n fifths
51
Equaltempered tuning
54
Tubeland
61
Curvature of Smooth Curves
62
Curves embedded in two dimensions
63
Curves embedded in three dimensions
64
Curvature of Smooth Surfaces
65
Gaussian curvature Extrinsic definition
66
Tubeland A fantasy
68
Triangular excess
71
Euclidean Geometry
73
The parallels axiom
75
Models of nonEuclidean geometries
77
The Calculating Eye
82
Graphs
84
The need for graphs
85
Materials for graphs
86
Clever people invented graphs
89
Coordinate Geometry
93
Synthetic versus analytic
94
Synthetic and analytic proofs
95
Straight lines
99
Conic sections
101
Algebra Rules
111
Algebra Anxiety
112
Arithmetic by Other Means
115
Symbolic algebra
116
Algebra and Geometry
120
Aljabr
121
Square root algorithms
122
The Root of the Problem
128
Patterns for Plane Ornaments
151
Wallpaper watching
158
The Magic Mirror
160
The Magic Writing
162
On the Shoulders of Giants
167
Integration Before Newton and Leibniz
168
Circular reasoning
170
Completing the estimate of pi
171
Differentiation Before Newton and Leibniz
172
Descartess discriminant method
173
Fermats difference quotient method
176
Galileos Lute
177
The inclined plane
179
SixMinute Calculus
184
Preliminaries
185
Functions
186
Limits
188
Continuity
189
The Damaged Dashboard
191
The broken speedometer
193
The derivative
194
The broken odometer
199
The definite integral
201
Roller Coasters
206
Time of descent
208
RollerCoaster Science
212
The Simplest Extremum Problems
213
The lifeguards calculation
215
A faster track
217
A roadbuilding project for three towns
219
Inequalities
220
The inequality of the arithmetic and geometric means
221
Cauchys inequality
223
The geometry of the cycloid
227
A differential equation
228
The restricted brachistochrone
230
The unrestricted brachistochrone
235
Glossary
243
Notes
249
References
257
Index
261
Copyright

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Page 83 - the words or the language, as they are written or spoken, do not seem to play any role in my mechanism of thought. . . . The physical entities which seem to serve as elements in thought are certain signs and more or less clear images which can be 'voluntarily
Page 1 - I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.
Page 142 - Tyger! Tyger! burning bright In the forests of the night, What immortal hand or eye Could frame thy fearful symmetry? In what distant deeps or skies Burnt the fire of thine eyes? On what wings dare he aspire? What the hand dare seize the fire? And what shoulder, & what art, Could twist the sinews of thy heart?
Page 24 - Magnitudes are said to be in the same ratio, the first to the second and the third to the fourth, when, if any equimultiples whatever be taken of the first and third, and any equimultiples whatever of the second and fourth, the former equimultiples alike exceed, are alike equal to, or alike fall short of, the latter equimultiples respectively taken in corresponding order.
Page 61 - Imagine a vast sheet of paper on which straight Lines, Triangles, Squares, Pentagons, Hexagons, and other figures, instead of remaining fixed in their places, move freely about, on or in the surface, but without the power of rising above or sinking below it, very much like shadows • — only hard and with luminous edges — and you will then have a pretty correct notion of my country and countrymen. Alas, a few years ago, I should have said " my universe " : but now my mind has been opened to higher...
Page 23 - A ratio is a sort of relation in respect of size between two magnitudes of the same kind. 4. Magnitudes are said to have a ratio to one another which are capable, when multiplied, of exceeding one another.
Page 112 - When I use a word," Humpty Dumpty said in rather a scornful tone, "it means just what I choose it to mean — neither more nor less." "The question is," said Alice, "whether you can make words mean so many different things.
Page 33 - ... they saw that the modifications and the ratios of the musical scales were expressible in numbers; - since, then, all other things seemed in their whole nature to be modelled on numbers, and numbers seemed to be the first things in the whole of nature, they supposed the elements of numbers to be the elements of all things, and the whole heaven to be a musical scale and a number.
Page 249 - Two unequal magnitudes being set out, if from the greater there be subtracted a magnitude greater than its half, and from that which is left a magnitude greater than its half, and if this process be repeated continually, there will be left some magnitude which will be less than the lesser magnitude set out.
Page 61 - I call our world Flatland, not because we call it so, but to make its nature clearer to you, my happy readers who are privileged to live in Space.

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