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1 | (10) |
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1 | (5) |
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2 | (2) |
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1.1.2 Equivalence relations and equivalence classes |
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4 | (2) |
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1.2 Some Elementary Combinatorics |
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6 | (5) |
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1.2.1 Mathematical induction |
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7 | (1) |
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1.2.2 The Binomial Theorem |
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8 | (3) |
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2 Groups and Fields: The Two Fundamental Notions of Algebra |
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11 | (46) |
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2.1 Groups and homomorphisms |
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11 | (12) |
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2.1.1 The Definition of a Group |
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12 | (1) |
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2.1.2 Some basic properties of groups |
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13 | (1) |
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2.1.3 The symmetric groups S(n) |
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14 | (1) |
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15 | (1) |
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2.1.5 Dihedral groups: generators and relations |
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16 | (2) |
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18 | (1) |
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2.1.7 Homomorphisms and Cayley's Theorem |
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19 | (4) |
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2.2 The Cosets of a Subgroup and Lagrange's Theorem |
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23 | (6) |
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2.2.1 The definition of a coset |
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23 | (2) |
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25 | (4) |
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2.3 Normal Subgroups and Quotient Groups |
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29 | (7) |
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29 | (1) |
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2.3.2 Constructing the quotient group G/H |
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30 | (2) |
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2.3.3 Euler's Theorem via quotient groups |
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32 | (2) |
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2.3.4 The First Isomorphism Theorem |
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34 | (2) |
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36 | (4) |
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2.4.1 The definition of a field |
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36 | (2) |
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2.4.2 Arbitrary sums and products |
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38 | (2) |
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2.5 The Basic Number Fields Q, R, and C |
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40 | (7) |
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2.5.1 The rational numbers Q |
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40 | (1) |
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40 | (1) |
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2.5.3 The complex numbers C |
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41 | (2) |
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43 | (2) |
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2.5.5 The Fundamental Theorem of Algebra |
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45 | (2) |
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47 | (10) |
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2.6.1 The prime fields Fp |
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47 | (1) |
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2.6.2 A four-element field |
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48 | (1) |
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2.6.3 The characteristic of a field |
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49 | (2) |
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2.6.4 Appendix: polynomials over a field |
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51 | (6) |
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57 | (28) |
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3.1 Introduction to matrices and matrix algebra |
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57 | (11) |
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58 | (1) |
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59 | (1) |
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3.1.3 Examples: matrices over F2 |
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60 | (1) |
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3.1.4 Matrix multiplication |
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61 | (2) |
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3.1.5 The Algebra of Matrix Multiplication |
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63 | (1) |
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3.1.6 The transpose of a matrix |
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64 | (1) |
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3.1.7 Matrices and linear mappings |
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65 | (3) |
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3.2 Reduced Row Echelon Form |
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68 | (9) |
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3.2.1 Reduced row echelon form and row operations |
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68 | (2) |
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3.2.2 Elementary matrices and row operations |
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70 | (2) |
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3.2.3 The row space and uniqueness of reduced row echelon form |
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72 | (5) |
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77 | (8) |
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3.3.1 The coefficient matrix of a linear system |
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77 | (1) |
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3.3.2 Writing the solutions: the homogeneous case |
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78 | (1) |
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3.3.3 The inhomogeneous case |
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79 | (3) |
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82 | (3) |
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4 Matrix Inverses, Matrix Groups and the LPDU Decomposition |
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85 | (28) |
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4.1 The Inverse of a Square Matrix |
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85 | (8) |
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4.1.1 The definition of the inverse |
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85 | (1) |
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4.1.2 Results on Inverses |
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86 | (2) |
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88 | (5) |
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93 | (7) |
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4.2.1 The definition of a matrix group |
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93 | (1) |
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4.2.2 Examples of matrix groups |
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94 | (1) |
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4.2.3 The group of permutation matrices |
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95 | (5) |
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4.3 The LPDU Factorization |
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100 | (13) |
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4.3.1 The basic ingredients: L, P, D, and U |
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100 | (2) |
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102 | (3) |
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4.3.3 Matrices with an LDU decomposition |
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105 | (2) |
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4.3.4 The Symmetric LDU Decomposition |
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107 | (1) |
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4.3.5 The Ranks of A and AT |
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108 | (5) |
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5 An Introduction to the Theory of Determinants |
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113 | (22) |
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5.1 An Introduction to the Determinant Function |
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114 | (5) |
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114 | (1) |
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5.1.2 The computation of a determinant |
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115 | (4) |
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5.2 The Definition of the Determinant |
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119 | (11) |
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5.2.1 The signature of a permutation |
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119 | (2) |
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5.2.2 The determinant via Leibniz's Formula |
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121 | (1) |
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5.2.3 Consequences of the definition |
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122 | (1) |
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5.2.4 The effect of row operations on the determinant |
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123 | (2) |
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5.2.5 The proof of the main theorem |
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125 | (1) |
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5.2.6 Determinants and LPDU |
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125 | (1) |
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5.2.7 A beautiful formula: Lewis Carroll's identity |
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126 | (4) |
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5.3 Appendix: Further Results on Determinants |
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130 | (5) |
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5.3.1 The Laplace expansion |
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130 | (2) |
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132 | (2) |
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5.3.3 The inverse of a matrix over Z |
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134 | (1) |
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135 | (62) |
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6.1 The Definition of a Vector Space and Examples |
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136 | (5) |
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6.1.1 The vector space axioms |
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136 | (2) |
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138 | (3) |
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6.2 Subspaces and Spanning Sets |
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141 | (4) |
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142 | (3) |
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6.3 Linear Independence and Bases |
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145 | (6) |
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6.3.1 The definition of linear independence |
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145 | (2) |
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6.3.2 The definition of a basis |
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147 | (4) |
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151 | (11) |
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6.4.1 The definition of dimension |
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151 | (1) |
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152 | (1) |
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6.4.3 The Dimension Theorem |
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153 | (3) |
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6.4.4 Finding a basis of the column space |
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156 | (1) |
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6.4.5 A Galois field application |
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157 | (5) |
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6.5 The Grassmann Intersection Formula |
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162 | (7) |
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6.5.1 Intersections and sums of subspaces |
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162 | (1) |
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6.5.2 Proof of the Grassmann intersection formula |
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163 | (2) |
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6.5.3 Direct sums of subspaces |
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165 | (2) |
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6.5.4 External direct sums |
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167 | (2) |
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169 | (14) |
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6.6.1 The definition of an inner product |
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169 | (1) |
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170 | (3) |
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6.6.3 Hermitian inner products |
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173 | (1) |
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174 | (1) |
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6.6.5 The existence of orthonormal bases |
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175 | (1) |
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6.6.6 Fourier coefficients |
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176 | (1) |
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6.6.7 The orthogonal complement of a subspace |
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177 | (1) |
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6.6.8 Hermitian inner product spaces |
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178 | (5) |
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6.7 Vector Space Quotients |
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183 | (4) |
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6.7.1 Cosets of a subspace |
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183 | (1) |
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6.7.2 The quotient V/W and the dimension formula |
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184 | (3) |
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6.8 Appendix: Linear Coding Theory |
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187 | (10) |
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6.8.1 The notion of a code |
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187 | (1) |
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6.8.2 Generating matrices |
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188 | (1) |
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188 | (2) |
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6.8.4 Error-correcting codes |
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190 | (2) |
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6.8.5 Cosets and perfect codes |
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192 | (1) |
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193 | (4) |
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197 | (42) |
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7.1 Definitions and Examples |
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197 | (8) |
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197 | (1) |
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7.1.2 The definition of a linear mapping |
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198 | (1) |
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198 | (2) |
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7.1.4 Matrix linear mappings |
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200 | (1) |
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7.1.5 An Application: rotations of the plane |
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201 | (4) |
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7.2 Theorems on Linear Mappings |
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205 | (6) |
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7.2.1 The kernel and image of a linear mapping |
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205 | (1) |
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7.2.2 The Rank-Nullity Theorem |
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206 | (1) |
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7.2.3 An existence theorem |
|
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206 | (1) |
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7.2.4 Vector space isomorphisms |
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207 | (4) |
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7.3 Isometries and Orthogonal Mappings |
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211 | (11) |
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7.3.1 Isometries and orthogonal linear mappings |
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211 | (1) |
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7.3.2 Orthogonal linear mappings on R" |
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212 | (1) |
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213 | (1) |
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213 | (2) |
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7.3.5 Projections on a general subspace |
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215 | (1) |
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7.3.6 Dimension two and the O(2, R)-dichotomy |
|
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216 | (2) |
|
7.3.7 The dihedral group as a subgroup of O(2, R) |
|
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218 | (1) |
|
7.3.8 The finite subgroups of O(2, R) |
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219 | (3) |
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7.4 Coordinates with Respect to a Basis and Matrices of Linear Mappings |
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222 | (10) |
|
7.4.1 Coordinates with respect to a basis |
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|
222 | (1) |
|
7.4.2 The change of basis matrix |
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223 | (2) |
|
7.4.3 The matrix of a linear mapping |
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|
225 | (1) |
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226 | (2) |
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228 | (1) |
|
7.4.6 The matrix of a composition T o S |
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228 | (1) |
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7.4.7 The determinant of a linear mapping |
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228 | (4) |
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7.5 Further Results on Mappings |
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|
232 | (7) |
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232 | (1) |
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232 | (2) |
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234 | (1) |
|
7.5.4 A characterization of the determinant |
|
|
235 | (4) |
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|
239 | (58) |
|
8.1 The Eigenvalue Problem and the Characteristic Polynomial |
|
|
239 | (12) |
|
8.1.1 First considerations: the eigenvalue problem for matrices |
|
|
240 | (1) |
|
8.1.2 The characteristic polynomial |
|
|
241 | (2) |
|
8.1.3 The characteristic polynomial of a 2 × 2 matrix |
|
|
243 | (1) |
|
8.1.4 A general formula for the characteristic polynomial |
|
|
244 | (7) |
|
8.2 Basic Results on Eigentheory |
|
|
251 | (8) |
|
8.2.1 Eigenpairs for linear mappings |
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|
251 | (1) |
|
8.2.2 Diagonalizable matrices |
|
|
252 | (2) |
|
8.2.3 A criterion for diagonaiizability |
|
|
254 | (1) |
|
8.2.4 The powers of a diagonalizable matrix |
|
|
255 | (1) |
|
8.2.5 The Fibonacci sequence as a dynamical system |
|
|
256 | (3) |
|
8.3 Two Characterizations of Diagonaiizability |
|
|
259 | (9) |
|
8.3.1 Diagonalization via eigenspace decomposition |
|
|
259 | (2) |
|
8.3.2 A test for diagonaiizability |
|
|
261 | (7) |
|
8.4 The Cayley--Hamilton Theorem |
|
|
268 | (6) |
|
8.4.1 Statement of the theorem |
|
|
268 | (1) |
|
8.4.2 The real and complex cases |
|
|
268 | (1) |
|
|
269 | (1) |
|
8.4.4 A proof of the Cayley--Hamilton theorem |
|
|
269 | (2) |
|
8.4.5 The minimal polynomial of a linear mapping |
|
|
271 | (3) |
|
8.5 Self Adjoint Mappings and the Principal Axis Theorem |
|
|
274 | (9) |
|
8.5.1 The notion of self-adjointness |
|
|
274 | (1) |
|
8.5.2 Principal Axis Theorem for self-adjoint linear mappings |
|
|
275 | (2) |
|
8.5.3 Examples of self-adjoint linear mappings |
|
|
277 | (1) |
|
8.5.4 A projection formula for symmetric matrices |
|
|
278 | (5) |
|
8.6 The Group of Rotations of R3 and the Platonic Solids |
|
|
283 | (11) |
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|
283 | (3) |
|
8.6.2 The Platonic solids |
|
|
286 | (1) |
|
8.6.3 The rotation group of a Platonic solid |
|
|
287 | (1) |
|
8.6.4 The cube and the octahedron |
|
|
288 | (2) |
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|
290 | (4) |
|
8.7 An Appendix on Field Extensions |
|
|
294 | (3) |
|
9 Unitary Diagonalization and Quadratic Forms |
|
|
297 | (22) |
|
9.1 Schur Triangularization and the Normal Matrix Theorem |
|
|
297 | (8) |
|
9.1.1 Upper triangularization via the unitary group |
|
|
298 | (1) |
|
9.1.2 The normal matrix theorem |
|
|
299 | (1) |
|
9.1.3 The Principal axis theorem: the short proof |
|
|
300 | (1) |
|
9.1.4 Other examples of normal matrices |
|
|
301 | (4) |
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|
305 | (8) |
|
9.2.1 Quadratic forms and congruence |
|
|
305 | (1) |
|
9.2.2 Diagonalization of quadratic forms |
|
|
306 | (1) |
|
9.2.3 Diagonalization in the real case |
|
|
307 | (1) |
|
|
308 | (1) |
|
9.2.5 Positive definite matrices |
|
|
308 | (2) |
|
9.2.6 The positive semidefinite case |
|
|
310 | (3) |
|
9.3 Sylvester's Law of Inertia and Polar Decomposition |
|
|
313 | (6) |
|
|
313 | (2) |
|
9.3.2 The polar decomposition of a complex linear mapping |
|
|
315 | (4) |
|
10 The Structure Theory of Linear Mappings |
|
|
319 | (18) |
|
10.1 The Jordan--Chevalley Theorem |
|
|
320 | (8) |
|
10.1.1 The statement of the theorem |
|
|
320 | (2) |
|
10.1.2 The multiplicative Jordan--Chevalley decomposition |
|
|
322 | (1) |
|
10.1.3 The proof of the Jordan--Chevalley theorem |
|
|
323 | (1) |
|
|
324 | (2) |
|
|
326 | (2) |
|
10.2 The Jordan Canonical Form |
|
|
328 | (9) |
|
10.2.1 Jordan blocks and string bases |
|
|
328 | (1) |
|
10.2.2 Jordan canonical form |
|
|
329 | (1) |
|
10.2.3 String bases and nilpotent endomorphisms |
|
|
330 | (3) |
|
10.2.4 Jordan canonical form and the minimal polynomial |
|
|
333 | (1) |
|
10.2.5 The conjugacy class of a nilpotent matrix |
|
|
334 | (3) |
|
11 Theorems on Group Theory |
|
|
337 | (46) |
|
11.1 Group Actions and the Orbit Stabilizer Theorem |
|
|
338 | (11) |
|
11.1.1 Group actions and G-sets |
|
|
338 | (3) |
|
11.1.2 The orbit stabilizer theorem |
|
|
341 | (1) |
|
|
341 | (2) |
|
|
343 | (1) |
|
11.1.5 Remarks on the center |
|
|
344 | (1) |
|
11.1.6 A fixed-point theorem for p-groups |
|
|
344 | (1) |
|
11.1.7 Conjugacy classes in the symmetric group |
|
|
345 | (4) |
|
11.2 The Finite Subgroups of SO(3, R) |
|
|
349 | (5) |
|
11.2.1 The order of a finite subgroup of SO(3, R) |
|
|
349 | (2) |
|
11.2.2 The order of a stabilizer Gp |
|
|
351 | (3) |
|
|
354 | (5) |
|
11.3.1 The first Sylow theorem |
|
|
354 | (1) |
|
11.3.2 The second Sylow theorem |
|
|
355 | (1) |
|
11.3.3 The third Sylow theorem |
|
|
355 | (1) |
|
11.3.4 Groups of order 12, 15, and 24 |
|
|
356 | (3) |
|
11.4 The Structure of Finite Abelian Groups |
|
|
359 | (5) |
|
|
359 | (2) |
|
11.4.2 The structure theorem for finite abelian groups |
|
|
361 | (1) |
|
11.4.3 The Chinese Remainder Theorem |
|
|
362 | (2) |
|
11.5 Solvable Groups and Simple Groups |
|
|
364 | (10) |
|
11.5.1 The definition of a solvable group |
|
|
364 | (2) |
|
11.5.2 The commutator subgroup |
|
|
366 | (1) |
|
11.5.3 An example: A(5) is simple |
|
|
367 | (2) |
|
11.5.4 Simple groups and the Jordan-Holder theorem |
|
|
369 | (1) |
|
11.5.5 A few brief remarks on Galois theory |
|
|
370 | (4) |
|
11.6 Appendix: S(n), Cryptography, and the Enigma |
|
|
374 | (5) |
|
11.6.1 Substitution ciphers via S(26) |
|
|
374 | (1) |
|
|
375 | (2) |
|
11.6.3 Rejewski's theorem on idempotents in S(n) |
|
|
377 | (2) |
|
|
379 | (4) |
|
12 Linear Algebraic Groups: an Introduction |
|
|
383 | (20) |
|
12.1 Linear Algebraic Groups |
|
|
383 | (15) |
|
12.1.1 Reductive and semisimple groups |
|
|
385 | (1) |
|
12.1.2 The classical groups |
|
|
386 | (1) |
|
|
386 | (2) |
|
|
388 | (2) |
|
|
390 | (1) |
|
12.1.6 The conjugacy of Borel subgroups |
|
|
391 | (1) |
|
12.1.7 The flag variety of a linear algebraic group |
|
|
392 | (1) |
|
12.1.8 The Bruhat decomposition of GL(n, F) |
|
|
393 | (2) |
|
12.1.9 The Bruhat decomposition of a reductive group |
|
|
395 | (1) |
|
12.1.10 Parabolic subgroups |
|
|
396 | (2) |
|
12.2 Linearly reductive groups |
|
|
398 | (5) |
|
12.2.1 Invariant subspaces |
|
|
398 | (1) |
|
|
398 | (1) |
|
|
399 | (1) |
|
|
400 | (3) |
Bibliography |
|
403 | (4) |
Index |
|
407 | |