CS223 · Chapter 5 · Annotated SlidesEigenvectors and Eigenvalues
Original
Overview

Eigenvectors and Eigenvalues

Eigenvectors Ax = λx, checking eigenvalues by solving (A − λI)x = 0, eigenspaces, eigenvalues of triangular matrices, and independence of eigenvectors for distinct eigenvalues.

How to read this page

Every original slide is shown unchanged. Yellow marks on a slide point to a numbered note: hover or tap a mark to jump to its note, and hover a note to see its marks. Questions tagged Past exam appeared on a real paper; Prediction questions are likely angles, not confirmed. Pick an answer to each question: a wrong pick tells you why it is wrong, so you can try again.

All 8 slides
  1. 1 CS 223: Computational Linear Algebra
  2. 2 Slide 2
  3. 3 How to determine whether a given How to determine whether a given
  4. 4 Slide 4
  5. 5 Slide 5
  6. 6 Slide 6
  7. 7 Eigenvalues of triangular matrix
  8. 8 Example:
Slide 1 / 8

CS 223: Computational Linear Algebra

Slide 1: CS 223: Computational Linear Algebra
Slide 2 / 8

Slide 2

Slide 2: Slide 2

Exam angle

Past exam · Final (231)

Related question: this topic is examined

Past exam · Final (232)

Related question: this topic is examined

PredictionQ1

The zero vector can be an eigenvector.

Slide 3 / 8

How to determine whether a given How to determine whether a given

Slide 3: How to determine whether a given How to determine whether a given
Slide 4 / 8

Slide 4

Slide 4: Slide 4
Slide 5 / 8

Slide 5

Slide 5: Slide 5

Notes

  1. Eigenspace of λ = Nul(A − λI); its dimension = number of free variables.

Slide 6 / 8

Slide 6

Slide 6: Slide 6
Slide 7 / 8

Eigenvalues of triangular matrix

Slide 7: Eigenvalues of triangular matrix

Notes

  1. Eigenvalues of a triangular matrix are its diagonal entries. 0 is an eigenvalue ⇔ A is not invertible. Eigenvectors for distinct eigenvalues are linearly independent.

Exam angle

PredictionQ1

The eigenvalues of [[3, 6, −8], [0, 0, 6], [0, 0, 2]] are:

Slide 8 / 8

Example:

Slide 8: Example: