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1 Geometry and Complex Arithmetic |
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1 | (60) |
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1 | (10) |
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1 | (3) |
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1.1.2 Bombelli's "Wild Thought" |
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4 | (2) |
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1.1.3 Some Terminology and Notation |
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6 | (2) |
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8 | (1) |
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1.1.5 Equivalence of Symbolic and Geometric Arithmetic |
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8 | (3) |
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11 | (5) |
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11 | (1) |
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1.2.2 Moving Particle Argument |
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12 | (1) |
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1.2.3 Power Series Argument |
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13 | (2) |
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1.2.4 Sine and Cosine in Terms of Euler's Formula |
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15 | (1) |
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16 | (17) |
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16 | (1) |
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16 | (2) |
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18 | (4) |
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22 | (3) |
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25 | (5) |
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1.3.6 Vectorial Operations |
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30 | (3) |
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1.4 Transformations and Euclidean Geometry* |
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33 | (18) |
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1.4.1 Geometry Through the Eyes of Felix Klein |
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33 | (5) |
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1.4.2 Classifying Motions |
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38 | (3) |
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1.4.3 Three Reflections Theorem |
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41 | (3) |
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1.4.4 Similarities and Complex Arithmetic |
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44 | (4) |
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1.4.5 Spatial Complex Numbers? |
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48 | (3) |
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51 | (10) |
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2 Complex Functions as Transformations |
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61 | (76) |
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61 | (3) |
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64 | (7) |
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2.2.1 Positive Integer Powers |
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64 | (2) |
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66 | (1) |
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67 | (4) |
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71 | (17) |
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2.3.1 The Mystery of Real Power Series |
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71 | (4) |
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2.3.2 The Disc of Convergence |
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75 | (3) |
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2.3.3 Approximating a Power Series with a Polynomial |
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78 | (1) |
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79 | (2) |
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2.3.5 Manipulating Power Series |
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81 | (2) |
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2.3.6 Finding the Radius of Convergence |
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83 | (3) |
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86 | (2) |
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2.4 The Exponential Function |
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88 | (6) |
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2.4.1 Power Series Approach |
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88 | (1) |
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2.4.2 The Geometry of the Mapping |
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89 | (1) |
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90 | (4) |
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94 | (6) |
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2.5.1 Definitions and Identities |
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94 | (1) |
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2.5.2 Relation to Hyperbolic Functions |
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95 | (2) |
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2.5.3 The Geometry of the Mapping |
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97 | (3) |
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100 | (10) |
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2.6.1 Example: Fractional Powers |
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100 | (3) |
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2.6.2 Single-Valued Branches of a Multifunction |
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103 | (3) |
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2.6.3 Relevance to Power Series |
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106 | (2) |
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2.6.4 An Example with Two Branch Points |
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108 | (2) |
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2.7 The Logarithm Function |
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110 | (5) |
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2.7.1 Inverse of the Exponential Function |
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110 | (2) |
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2.7.2 The Logarithmic Power Series |
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112 | (1) |
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113 | (2) |
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2.8 Averaging over Circles* |
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115 | (10) |
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115 | (3) |
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2.8.2 Averaging over Regular Polygons |
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118 | (3) |
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2.8.3 Averaging over Circles |
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121 | (4) |
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125 | (12) |
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3 Mobius Transformations and Inversion |
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137 | (76) |
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137 | (2) |
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3.1.1 Definition and Significance of Mobius Transformations |
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137 | (1) |
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3.1.2 The Connection with Einstein's Theory of Relativity* |
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138 | (1) |
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3.1.3 Decomposition into Simple Transformations |
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139 | (1) |
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139 | (14) |
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3.2.1 Preliminary Definitions and Facts |
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139 | (3) |
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3.2.2 Preservation of Circles |
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142 | (2) |
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3.2.3 Constructing Inverse Points Using Orthogonal Circles |
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144 | (3) |
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3.2.4 Preservation of Angles |
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147 | (2) |
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3.2.5 Preservation of Symmetry |
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149 | (1) |
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3.2.6 Inversion in a Sphere |
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150 | (3) |
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3.3 Three Illustrative Applications of Inversion |
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153 | (4) |
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3.3.1 A Problem on Touching Circles |
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153 | (1) |
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3.3.2 A Curious Property of Quadrilaterals with Orthogonal Diagonals |
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154 | (2) |
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156 | (1) |
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157 | (11) |
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3.4.1 The Point at Infinity |
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157 | (1) |
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3.4.2 Stereographic Projection |
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158 | (4) |
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3.4.3 Transferring Complex Functions to the Sphere |
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162 | (1) |
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3.4.4 Behaviour of Functions at Infinity |
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163 | (2) |
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3.4.5 Stereographic Formulae* |
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165 | (3) |
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3.5 Mobius Transformations: Basic Results |
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168 | (9) |
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3.5.1 Preservation of Circles, Angles, and Symmetry |
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168 | (1) |
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3.5.2 Non-Uniqueness of the Coefficients |
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169 | (1) |
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170 | (1) |
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171 | (1) |
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3.5.5 Fixed Points at Infinity |
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172 | (2) |
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174 | (3) |
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3.6 Mobius Transformations as Matrices* |
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177 | (7) |
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3.6.1 Empirical Evidence of a Link with Linear Algebra |
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177 | (1) |
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3.6.2 The Explanation: Homogeneous Coordinates |
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178 | (2) |
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3.6.3 Eigenvectors and Eigenvalues* |
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180 | (2) |
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3.6.4 Rotations of the Sphere as Mobius Transformations* |
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182 | (2) |
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3.7 Visualization and Classification* |
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184 | (10) |
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184 | (2) |
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3.7.2 Elliptic, Hyperbolic, and Loxodromic Transformations |
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186 | (3) |
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3.7.3 Local Geometric Interpretation of the Multiplier |
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189 | (1) |
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3.7.4 Parabolic Transformations |
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190 | (1) |
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3.7.5 Computing the Multiplier* |
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191 | (1) |
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3.7.6 Eigenvalue Interpretation of the Multiplier* |
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192 | (2) |
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3.8 Decomposition into 2 or 4 Reflections* |
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194 | (5) |
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194 | (1) |
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194 | (2) |
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196 | (1) |
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197 | (1) |
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198 | (1) |
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3.9 Automorphisms of the Unit Disc* |
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199 | (6) |
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3.9.1 Counting Degrees of Freedom |
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199 | (1) |
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3.9.2 Finding the Formula via the Symmetry Principle |
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200 | (1) |
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3.9.3 Interpreting the Simplest Formula Geometrically* |
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201 | (3) |
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3.9.4 Introduction to Riemann's Mapping Theorem |
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204 | (1) |
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205 | (8) |
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4 Differentiation: The Amplitwist Concept |
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213 | (32) |
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213 | (1) |
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4.2 A Puzzling Phenomenon |
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213 | (3) |
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4.3 Local Description of Mappings in the Plane |
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216 | (4) |
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216 | (1) |
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4.3.2 The Jacobian Matrix |
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217 | (1) |
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4.3.3 The Amplitwist Concept |
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218 | (2) |
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4.4 The Complex Derivative as Amplitwist |
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220 | (5) |
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4.4.1 The Real Derivative Re-examined |
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220 | (1) |
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4.4.2 The Complex Derivative |
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221 | (2) |
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223 | (1) |
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224 | (1) |
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225 | (2) |
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227 | (4) |
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227 | (1) |
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4.6.2 Conformality Throughout a Region |
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228 | (2) |
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4.6.3 Conformality and the Riemann Sphere |
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230 | (1) |
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231 | (3) |
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4.7.1 Degrees of Crushing |
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231 | (1) |
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4.7.2 Breakdown of Conformality |
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232 | (1) |
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233 | (1) |
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4.8 The Cauchy-Riemann Equations |
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234 | (5) |
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234 | (1) |
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4.8.2 The Geometry of Linear Transformations |
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235 | (2) |
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4.8.3 The Cauchy-Riemann Equations |
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237 | (2) |
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239 | (6) |
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5 Further Geometry of Differentiation |
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245 | (58) |
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5.1 Cauchy--Riemann Revealed |
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245 | (4) |
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245 | (1) |
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245 | (2) |
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247 | (2) |
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5.2 An Intimation of Rigidity |
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249 | (3) |
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5.3 Visual Differentiation of log(z) |
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252 | (2) |
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5.4 Rules of Differentiation |
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254 | (3) |
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254 | (1) |
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255 | (1) |
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5.4.3 Addition and Multiplication |
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256 | (1) |
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5.5 Polynomials, Power Series, and Rational Functions |
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257 | (3) |
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257 | (1) |
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257 | (2) |
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259 | (1) |
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5.6 Visual Differentiation of the Power Function |
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260 | (2) |
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5.7 Visual Differentiation of exp(z) |
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262 | (2) |
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5.8 Geometric Solution of E' = E |
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264 | (2) |
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5.9 An Application of Higher Derivatives: Curvature* |
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266 | (8) |
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266 | (1) |
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5.9.2 Analytic Transformation of Curvature |
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267 | (3) |
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270 | (4) |
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5.10 Celestial Mechanics* |
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274 | (7) |
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5.10.1 Central Force Fields |
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274 | (1) |
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5.10.2 Two Kinds of Elliptical Orbit |
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274 | (3) |
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5.10.3 Changing the First into the Second |
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277 | (1) |
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5.10.4 The Geometry of Force |
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278 | (1) |
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279 | (1) |
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5.10.6 The Kasner--Arnol'd Theorem |
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280 | (1) |
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5.11 Analytic Continuation* |
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281 | (12) |
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281 | (2) |
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283 | (1) |
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284 | (2) |
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5.11.4 Preservation of Identities |
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286 | (1) |
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5.11.5 Analytic Continuation via Reflections |
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286 | (7) |
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293 | (10) |
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6 Non-Euclidean Geometry* |
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303 | (82) |
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303 | (13) |
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303 | (2) |
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6.1.2 Some Facts from Non-Euclidean Geometry |
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305 | (2) |
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6.1.3 Geometry on a Curved Surface |
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307 | (2) |
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6.1.4 Intrinsic versus Extrinsic Geometry |
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309 | (2) |
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311 | (2) |
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6.1.6 Surfaces of Constant Curvature |
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313 | (2) |
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6.1.7 The Connection with Mobius Transformations |
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315 | (1) |
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316 | (17) |
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6.2.1 The Angular Excess of a Spherical Triangle |
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316 | (1) |
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6.2.2 Motions of the Sphere: Spatial Rotations and Reflections |
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317 | (4) |
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6.2.3 A Conformal Map of the Sphere |
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321 | (4) |
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6.2.4 Spatial Rotations as Mobius Transformations |
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325 | (4) |
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6.2.5 Spatial Rotations and Quaternions |
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329 | (4) |
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333 | (41) |
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6.3.1 The Tractrix and the Pseudosphere |
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333 | (2) |
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6.3.2 The Constant Negative Curvature of the Pseudosphere* |
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335 | (1) |
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6.3.3 A Conformal Map of the Pseudosphere |
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336 | (3) |
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6.3.4 Beltrami's Hyperbolic Plane |
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339 | (3) |
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6.3.5 Hyperbolic Lines and Reflections |
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342 | (5) |
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6.3.6 The Bolyai--Lobachevsky Formula* |
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347 | (1) |
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6.3.7 The Three Types of Direct Motion |
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348 | (5) |
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6.3.8 Decomposing an Arbitrary Direct Motion into Two Reflections |
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353 | (4) |
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6.3.9 The Angular Excess of a Hyperbolic Triangle |
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357 | (2) |
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6.3.10 The Beltrami--Poincare Disc |
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359 | (4) |
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6.3.11 Motions of the Beltrami--Poincare Disc |
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363 | (4) |
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6.3.12 The Hemisphere Model and Hyperbolic Space |
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367 | (7) |
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374 | (11) |
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7 Winding Numbers and Topology |
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385 | (44) |
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385 | (3) |
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385 | (1) |
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7.1.2 What Does "Inside" Mean? |
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386 | (1) |
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7.1.3 Finding Winding Numbers Quickly |
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387 | (1) |
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7.2 Hopf's Degree Theorem |
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388 | (5) |
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388 | (2) |
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7.2.2 Loops as Mappings of the Circle* |
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390 | (1) |
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391 | (2) |
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7.3 Polynomials and the Argument Principle |
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393 | (1) |
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7.4 A Topological Argument Principle* |
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394 | (9) |
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7.4.1 Counting Preimages Algebraically |
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394 | (2) |
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7.4.2 Counting Preimages Geometrically |
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396 | (2) |
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7.4.3 What's Topologically Special About Analytic Functions? |
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398 | (1) |
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7.4.4 A Topological Argument Principle |
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399 | (2) |
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401 | (2) |
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403 | (2) |
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403 | (1) |
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7.5.2 The Fundamental Theorem of Algebra |
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404 | (1) |
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7.5.3 Brouwer's Fixed Point Theorem* |
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404 | (1) |
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405 | (2) |
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7.6.1 Maximum-Modulus Theorem |
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405 | (2) |
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407 | (1) |
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7.7 The Schwarz--Pick Lemma* |
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407 | (7) |
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407 | (2) |
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7.7.2 Liouville's Theorem |
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409 | (2) |
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411 | (3) |
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7.8 The Generalized Argument Principle |
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414 | (6) |
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414 | (2) |
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7.8.2 Poles and Essential Singularities |
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416 | (3) |
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419 | (1) |
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420 | (9) |
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8 Complex Integration: Cauchy's Theorem |
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429 | (56) |
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429 | (1) |
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430 | (6) |
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430 | (2) |
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8.2.2 The Trapezoidal Rule |
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432 | (2) |
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8.2.3 Geometric Estimation of Errors |
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434 | (2) |
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436 | (6) |
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8.3.1 Complex Riemann Sums |
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436 | (3) |
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439 | (1) |
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8.3.3 A Useful Inequality |
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440 | (1) |
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8.3.4 Rules of Integration |
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441 | (1) |
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442 | (5) |
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442 | (2) |
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444 | (2) |
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446 | (1) |
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447 | (3) |
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447 | (1) |
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8.5.2 Area Interpretation |
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448 | (2) |
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450 | (1) |
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450 | (7) |
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8.6.1 Integration along a Circular Arc |
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450 | (2) |
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8.6.2 Complex Inversion as a Limiting Case* |
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452 | (1) |
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8.6.3 General Contours and the Deformation Theorem |
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453 | (1) |
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8.6.4 A Further Extension of the Theorem |
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454 | (1) |
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455 | (2) |
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8.7 The Exponential Mapping |
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457 | (1) |
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8.8 The Fundamental Theorem |
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458 | (8) |
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458 | (1) |
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459 | (1) |
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8.8.3 The Fundamental Theorem |
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460 | (2) |
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8.8.4 The Integral as Antiderivative |
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462 | (3) |
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8.8.5 Logarithm as Integral |
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465 | (1) |
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8.9 Parametric Evaluation |
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466 | (1) |
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467 | (5) |
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8.10.1 Some Preliminaries |
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467 | (2) |
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469 | (3) |
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8.11 The General Cauchy Theorem |
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472 | (3) |
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472 | (1) |
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473 | (1) |
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8.11.3 A Simpler Explanation |
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474 | (1) |
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8.12 The General Formula of Contour Integration |
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475 | (3) |
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478 | (7) |
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9 Cauchy's Formula and Its Applications |
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485 | (26) |
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485 | (4) |
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485 | (1) |
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486 | (1) |
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9.1.3 Gauss's Mean Value Theorem |
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487 | (1) |
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9.1.4 A Second Explanation and the General Cauchy Formula |
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488 | (1) |
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9.2 Infinite Differentiability and Taylor Series |
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489 | (4) |
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9.2.1 Infinite Differentiability |
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489 | (2) |
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491 | (2) |
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493 | (8) |
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9.3.1 Laurent Series Centred at a Pole |
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493 | (1) |
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9.3.2 A Formula for Calculating Residues |
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494 | (1) |
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9.3.3 Application to Real Integrals |
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495 | (2) |
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9.3.4 Calculating Residues using Taylor Series |
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497 | (1) |
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9.3.5 Application to Summation of Series |
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498 | (3) |
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9.4 Annular Laurent Series |
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501 | (5) |
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501 | (1) |
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502 | (4) |
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506 | (5) |
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10 Vector Fields: Physics and Topology |
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511 | (26) |
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511 | (7) |
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10.1.1 Complex Functions as Vector Fields |
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511 | (2) |
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10.1.2 Physical Vector Fields |
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513 | (2) |
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10.1.3 Flows and Force Fields |
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515 | (1) |
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516 | (2) |
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10.2 Winding Numbers and Vector Fields* |
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518 | (7) |
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10.2.1 The Index of a Singular Point |
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518 | (4) |
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10.2.2 The Index According to Poincare |
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522 | (1) |
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523 | (2) |
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10.3 Flows on Closed Surfaces* |
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525 | (7) |
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10.3.1 Formulation of the Poincare--Hopf Theorem |
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525 | (2) |
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10.3.2 Defining the Index on a Surface |
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527 | (2) |
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10.3.3 An Explanation of the Poincare--Hopf Theorem |
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529 | (3) |
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532 | (5) |
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11 Vector Fields and Complex Integration |
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537 | (40) |
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537 | (10) |
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537 | (2) |
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539 | (3) |
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11.1.3 Local Flux and Local Work |
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542 | (1) |
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11.1.4 Divergence and Curl in Geometric Form* |
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543 | (2) |
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11.1.5 Divergence-Free and Curl-Free Vector Fields |
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545 | (2) |
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11.2 Complex Integration in Terms of Vector Fields |
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547 | (15) |
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11.2.1 The Polya Vector Field |
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547 | (2) |
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549 | (1) |
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11.2.3 Example: Area as Flux |
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550 | (1) |
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11.2.4 Example: Winding Number as Flux |
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551 | (2) |
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11.2.5 Local Behaviour of Vector Fields* |
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553 | (2) |
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555 | (1) |
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556 | (1) |
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11.2.8 Negative Powers and Multipoles |
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557 | (3) |
|
11.2.9 Multipoles at Infinity |
|
|
560 | (1) |
|
11.2.10 Laurent's Series as a Multipole Expansion |
|
|
561 | (1) |
|
11.3 The Complex Potential |
|
|
562 | (12) |
|
|
562 | (1) |
|
11.3.2 The Stream Function |
|
|
563 | (2) |
|
11.3.3 The Gradient Field |
|
|
565 | (2) |
|
11.3.4 The Potential Function |
|
|
567 | (2) |
|
11.3.5 The Complex Potential |
|
|
569 | (3) |
|
|
572 | (2) |
|
|
574 | (3) |
|
12 Flows and Harmonic Functions |
|
|
577 | (76) |
|
|
577 | (6) |
|
|
577 | (3) |
|
|
580 | (3) |
|
12.2 Conformal Invariance |
|
|
583 | (4) |
|
12.2.1 Conformal Invariance of Harmonicity |
|
|
583 | (1) |
|
12.2.2 Conformal Invariance of the Laplacian |
|
|
584 | (2) |
|
12.2.3 The Meaning of the Laplacian |
|
|
586 | (1) |
|
12.3 A Powerful Computational Tool |
|
|
587 | (3) |
|
12.4 The Complex Curvature Revisited* |
|
|
590 | (8) |
|
12.4.1 Some Geometry of Harmonic Equipotentials |
|
|
590 | (1) |
|
12.4.2 The Curvature of Harmonic Equipotentials |
|
|
590 | (4) |
|
12.4.3 Further Complex Curvature Calculations |
|
|
594 | (1) |
|
12.4.4 Further Geometry of the Complex Curvature |
|
|
595 | (3) |
|
12.5 Flow Around an Obstacle |
|
|
598 | (15) |
|
|
598 | (1) |
|
|
599 | (5) |
|
12.5.3 The Method of Images |
|
|
604 | (7) |
|
12.5.4 Mapping One Flow Onto Another |
|
|
611 | (2) |
|
12.6 The Physics of Riemann's Mapping Theorem |
|
|
613 | (17) |
|
|
613 | (2) |
|
12.6.2 Exterior Mappings and Flows Round Obstacles |
|
|
615 | (3) |
|
12.6.3 Interior Mappings and Dipoles |
|
|
618 | (2) |
|
12.6.4 Interior Mappings, Vortices, and Sources |
|
|
620 | (4) |
|
12.6.5 An Example: Automorphisms of the Disc |
|
|
624 | (2) |
|
|
626 | (4) |
|
|
630 | (19) |
|
|
630 | (1) |
|
12.7.2 Schwarz's Interpretation |
|
|
631 | (3) |
|
12.7.3 Dirichlet's Problem for the Disc |
|
|
634 | (3) |
|
12.7.4 The Interpretations of Neumann and Bocher |
|
|
637 | (6) |
|
12.7.5 Green's General Formula |
|
|
643 | (6) |
|
|
649 | (4) |
Bibliography |
|
653 | (8) |
Index |
|
661 | |