Linear algebra 2
Section outline
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Definition, properties with respect to matrix operations - transposition, elementary row operations, matrix product, inverse
Linearity of the determinant
Determinant calculation - by Gauss elimination and by Laplace expansion
Adjoint matrix
Cramer's rule
Geometric meaning of the determinant
Application - number of spanning trees of a graph
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Polynomial operations - addition, subtraction, products, division with a remainder
Fermat's little theorem
Roots, the fundamental theorem of algebra (without a proof)
Decomposition into monomials
Representation of polynomials
Vandermonde matrix and its regularity
Lagrange interpolation
Applications - secret sharing, fast integer multiplication
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Eigenvalues and eigenvectors of linear maps and square matrices
Properties of eigenvectors (subspaces, linear independence)
Characteristic polynomial and its coefficients
Calculation of eigenvalues and eigenvectors
Application in systems of differential equations
Cayley-Hamilton theorem
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Similar matrices
Diagonalization - definition, existence via eigenvectors
Jordan normal form (without a proof)
Diagonalization of symmetric and Hermitian matrices
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Inner product, norm
Cauchy-Schwarz inequality
Orthogonality, orthonormal bases
Orthogonal projection, Gramm-Schmidt orthonormalization
Isometry
Orthogonal complement
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Gram matrix
Positive definite matrices
Cholesky factorization
Other characterizations
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Bilinear and quadratic forms
Matrices of forms
Diagonalization of quadratic forms
Sylvester's law of inertia
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Number of spanning trees - see the section of determinants
Number of even subgraphs
Maximum number of lines spanning the same angle