Linear Algebra

Mathematics I · ADIN001NABB · Corvinus University of Budapest

Linear Algebra

Fall semester 2026–27, with Gyula Magyarkuti. Slides, quiz dates, the weekly schedule, and a lab where you can push matrices around and see what they do.

Quizzes in weeks 3, 6, 9 and 12
Identity

Course

How the course works

The syllabus can be downloaded here. The most important parts are summarised below.

Essentials

  • Attendance is compulsory in the classes.
  • Final exams: 16 Dec, 5 Jan, 12 Jan.
  • Office hours: S 208/b, Monday 19.00. Register by e-mail no later than 7pm of the day before.
  • All regulations and conditions are governed by the University’s Code of Studies and Examinations.

Mini quizzes

  1. Quiz 1 · Week 3Sep 28
  2. Quiz 2 · Week 6Oct 19
  3. Quiz 3 · Week 9Nov 16
  4. Quiz 4 · Week 12Dec 7

Grading

Four quizzes worth 5 points each, plus a final written exam worth 30. That makes 50 points in total.

total = (q₁, q₂, q₃, q₄, e) · (1, 1, 1, 1, 1) ≤ 50

Schedule

Week by week

Each week links to its slides. The green links jump to a lab experiment for that topic.

  1. Week1

    Elements

    • Vectors
    • Linear combination
    • Subspaces
    • Linearly independent and dependent systems
    • Basic properties of independent systems
    • Gauss–Jordan elimination
  2. Week2

    Basis

    • Basis
    • Basis transformation
    • Applications
  3. Week3

    Matrix

    • Inner product
    • Concept of matrices
    • Operations on matrices
    • Multiplication of matrices
    • Powers of a matrix
    • Rank theorem
  4. Week4

    Factoring matrices

    • System of linear equations
    • Factoring matrices
    • Rank–nullity theorem
    • Problems
  5. Week5

    System of linear equations

    • Solution of homogeneous linear systems
    • Solution of non-homogeneous linear systems
  6. Week6

    The inverse matrix

    • Matrix equations
    • Inverse matrix
  7. Week7

    Quadratic forms

    • Definition of quadratic forms
    • Dyadic decomposition
      • A dyad is the matrix of a complete square
      • High-school method for small sizes
      • Professional method with Gaussian elimination
    • Problems
    • Definiteness of a quadratic form
    • Summary
  8. Week8

    Determinant

    • Parity of permutations
    • The concept of the determinant
    • Special cases of size 1, 2 and 3
    • Properties
    • Computing the determinant with Gauss–Jordan elimination
    • Expansion by minors
    • Characteristic polynomial
  9. Week9

    Diagonalising a matrix

    • Eigenvalues and eigenvectors
    • Finding them with G–J elimination
    • Diagonalisable matrices
    • Problems
  10. Week10

    Preparation for the final exam

    • Mock exam
    • Review problems

Lab

Play with the ideas

Five small games, one for each big idea of the course. Each has a free-play mode and a challenge mode. Scores stay in your own browser and nothing here is graded.

Weeks 3, 4, 6, 8, 9

Matrix sandbox

A 2×2 matrix is decided by where it sends the two basis vectors. Its first column is where î lands, its second is where ĵ lands. Drag the arrow tips or type numbers. The gold square shows the determinant as an area, and dashed lines mark the eigenvectors.

A =

Weeks 1, 2

Level 1

Span game

Land on the gold ring using only u and v. Pick α and β so that αu + βv hits the target. Watch out for traps: if u and v are parallel, they only span a line, and the target may be out of reach. Every three hits takes you up a level.

Score0
Streak0
Best0
0
0

Weeks 1, 5, 6

Gauss–Jordan elimination

A random 3×3 system, worked in exact fractions. In Quiz me mode you choose each row operation, and a wrong choice tells you what it would break. In Watch mode you just step through. The green cell is the pivot and the gold row is the one that just changed.

The system

Augmented matrix

Next row operation?

Weeks 7, 9

Quadratic landscapes

Q(x, y) = a·x² + 2b·xy + c·y², seen from above. Green is where Q is positive, rose where it is negative, and the lines are contour lines. Sylvester’s criterion reads the shape off the leading principal minors. The dashed lines are the eigenvectors of the symmetric matrix, and they are always perpendicular.

Weeks 3, 9

Matrix powers race to an eigenvalue

A¹ =
Ratio
λ₁
Error

In the wild

Where this shows up after the exam

Week 9 · eigenvectors

Google’s PageRank

P·r = 1·r

The original ranking of web pages is the eigenvector for eigenvalue 1 of a huge matrix of link probabilities.

Week 6 · inverse matrix

Leontief’s economy

x = (I − A)⁻¹·d

How much each sector must produce to meet final demand d. This input–output model won Wassily Leontief the 1973 Nobel Prize in economics.

Week 7 · quadratic forms

Portfolio risk

σ² = wᵀ·Σ·w

The variance of a portfolio with weights w is a quadratic form in the covariance matrix Σ. It is positive semidefinite, because a variance can’t be negative.

Week 3 · matrix product

Every video game frame

v′ = M·v

Each rotation, zoom and camera move is a matrix multiplication, applied to millions of vertices per frame on the graphics card.