LibreTimes

Search results for “number-theory”

87 results

Eigenvectors and Eigenvalues

2026TheorySergey

Eigenvectors and eigenvalues, the characteristic equation, eigenspaces, and diagonalization of matrices.
0
170

Properties of Determinants

2026TheorySergey

The basic properties of determinants with brief proofs, and their use in simplifying computations.
0
260

Some examples of algebraic groups

2026TheorySean Cotner

Two pathological phenomena for algebraic groups over general bases — a group degenerating between the multiplicative and additive group across a DVR, and a non-affine identity component — built as centralizers in SL_n.

0
180

Determinant via Permutations

2026TheorySergey

The direct definition of a determinant via permutations: inversions, parity, and a sum of n! terms.

0
170

Inverse Matrices

2026TheorySergey

Nonsingular matrices, the invertibility criterion, the adjugate-matrix formula, and the Gauss–Jordan method.
0
120

Matrix Rank

2026TheorySergey

Minors and the rank of a matrix, invariance of rank under elementary transformations, and a practical method for computing it.
0
190

Basis, Dimension, and Span

2026TheorySergey

Linear dependence of vectors, basis and coordinates, dimension, subspaces, and linear span.
0
220

Determinant

2026TheorySergey

The determinant of a square matrix — its meaning, minors and cofactors, Laplace expansion, and computation methods.
0
190

Vector calculus. Green's theorem

2026Problem sheetSergey

A contour integral as a double integral: the hypotheses of Green's theorem, orientation of the contour, area as a contour integral, closing an open arc, an annulus, a singular point inside the contour.
0
260

Vector calculus. Stokes' theorem. Circulation

2026Problem sheetSergey

Circulation of a field as the flux of its curl: computing the curl, matching the orientation of the contour and the normal, circulation computed two ways.
0
310

IMO 1962

2026Problem sheet

International mathematics competition for pre-university students, held annually since 1959. Six problems over two days.
0
340

IMO 1987

2026Problem sheet

International mathematics competition for pre-university students, held annually since 1959. Six problems over two days.
0
290

IMO 1959

2026Problem sheet

International mathematics competition for pre-university students, held annually since 1959. Six problems over two days.
0
310

IMO 1969

2026Problem sheet

International mathematics competition for pre-university students, held annually since 1959. Six problems over two days.
0
280

IMO 1971

2026Problem sheet

International mathematics competition for pre-university students, held annually since 1959. Six problems over two days.
0
180

Basic Operations on Matrices

2026TheorySergey

Addition, scalar multiplication, transposition and multiplication of matrices, along with subtraction, powers, and trace.
0
150

IMO 1961

2026Problem sheet

International mathematics competition for pre-university students, held annually since 1959. Six problems over two days.
0
240

IMO 1966

2026Problem sheet

International mathematics competition for pre-university students, held annually since 1959. Six problems over two days.
0
190