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Linear Algebra
Matrices, determinants, inverses, row reduction and eigenvalues.
Tanulságok
det [[1,2],[3,4]]
Core
Matrix inverse
The 2×2 formula and Gauss-Jordan elimination for the rest.
inverse of [[1,2],[3,4]]
Advanced
Eigenvalues and eigenvectors
The characteristic polynomial and the directions a matrix only stretches.
eigenvalues of [[2,1],[1,2]]
Introductory
Matrix multiplication
Rows times columns, entry by entry.
[[1,2],[3,4]] * [[5,6],[7,8]]
Core
Row reduction
Gaussian elimination, rank and solving Ax = b.
rref [[1,2,3],[4,5,6],[7,8,9]]
Core
Vector spaces, span and linear independence
The axioms, spanning sets, independence, basis and dimension.
rank of [[1,2],[2,4]]
Core
Orthogonality, projections and least squares
Dot products, orthonormal bases, projection onto a subspace, fitting a line.
inverse of [[2,1],[1,1]]
Core
Diagonalisation and matrix powers
A = PDP⁻¹, computing Aⁿ, and the matrices that cannot be diagonalised.
eigenvalues of [[4,1],[2,3]]
Core
Linear transformations and change of basis
Matrices as maps, kernel and image, and the same map in different coordinates.
[[0,-1],[1,0]] * [[1],[0]]
Vectors and the matrices that move them. Every operation is shown row by row, and 2×2 and 3×3 matrices are drawn in 3D so you can see what a determinant or an eigenvector actually is.
További tanulságok
Systems of Linear Equations
Matrices
Vector Spaces
Linear Transformations
Preliminaries
Systems of Equations and Inequalities
Structure
Geometry and spectra
A nyílt szövegek néhány tanulságát a következőképpen igazítják: Beezer, A First Course in Linear Algebra, OpenStax Precalculus 2e, Wikipedia. Minden lecke oldal megnevezi a forrását és az engedélyét.
Itt használt szimbólumok
Koppintson a teljes definícióra, a képre és arra, hogy mit jelent minden betű.
Kérdések, amiket az emberek feltesznek
What does a determinant mean geometrically?
It is the factor by which the matrix scales area (2×2) or volume (3×3), with a negative sign if orientation flips. Zero means the matrix flattens space and cannot be undone.
What is an eigenvector?
A direction the matrix does not turn: it only stretches it by the eigenvalue. Along eigenvectors a complicated matrix acts like multiplication by a number.
Why is matrix multiplication not commutative?
Because a matrix is a transformation and AB means "do B, then A". Rotating then reflecting is not the same as reflecting then rotating.
Írja be vagy rajzolja le a megoldó oldalra: minden lépés, egy kép, a válasz elrejtve, amíg nem kérdezed. Megoldás →
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