Change of basis | Chapter 13, Essence of linear algebra

Change of basis | Chapter 13, Essence of linear algebra

🎙 3Blue1Brown 👥 8.6M 📅 September 11, 2016 ⏱ 12 min 👁 2.5M 📄 tutorial 🧭 2026-08-28
Available in: English (current) Français

Keywords

change of basiscoordinate systemslinear transformationmatrix multiplicationbasis vectors

Summary

This video from the ‘Essence of linear algebra’ series explains the concept of changing basis in linear algebra. It begins by reviewing how coordinates are defined in a standard basis and introduces the idea of alternative basis vectors, using the example of a friend named Jennifer who uses different basis vectors. The video demonstrates how to translate coordinates between different coordinate systems, showing that a matrix whose columns are the new basis vectors (expressed in the standard basis) converts coordinates from the new system to the standard one, and its inverse does the opposite. It then extends this to transformations, explaining how to represent a linear transformation in a different basis using the formula A^(-1) M A. The video emphasizes the geometric intuition behind these operations, using animations to illustrate the concepts. It concludes by hinting that the next video on eigenvectors and eigenvalues will provide an important application of changing basis.

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Critical Evaluation

Value of the Information & Strength of the Argument

The video provides high-value educational content, offering clear and intuitive explanations of a fundamental linear algebra concept. The argumentation is solid, building from basic definitions to more complex ideas in a logical sequence. The use of a concrete example (Jennifer’s basis) and visual animations greatly enhances understanding. The explanation of the ’empathy’ behind the A^(-1) M A formula is particularly insightful, providing a deep conceptual understanding rather than just procedural knowledge.

Scientific Rigor, Source Quality, Title Accuracy

The scientific rigor is high; the mathematical content is accurate and well-presented. The video does not cite external sources, but it is part of a well-established educational series known for its correctness. The title accurately describes the content. The description includes links to the channel’s Patreon and homepage, which are not directly related to the content but are standard for the channel. The video’s pedagogical approach is rigorous and aligns with standard linear algebra curricula.

161 words

Title / Content Match

The title accurately reflects the content, which focuses on the concept of changing basis in linear algebra.

Quality & Reliability

9/10

The video is a well-structured tutorial by a renowned mathematics educator, with clear explanations and visualizations. The content is mathematically accurate and aligns with standard linear algebra concepts. The channel has a strong reputation for educational quality.

Key Moments

Cited Sources

  • 3Blue1Brown Support Page — Link in video description for supporting the channel.
  • 3Blue1Brown Home Page — Link in video description to the channel's homepage.

Concurring Sources

Contribution & Novelties

This video provides a unique and highly effective visual and intuitive explanation of change of basis, a topic often taught purely algebraically. It emphasizes the geometric interpretation and the concept of ‘mathematical empathy’, making the abstract concept accessible. The use of animations to show the transformation of the grid and the coordinate systems is a significant contribution to math education.

Pour aller plus loin :

110 words

Radar Profile

The radar profile shows very high scores in information quality and reliability, with slightly lower but still strong scores in information quantity and technical level. This indicates a video that is both accurate and comprehensive, though it assumes some prior knowledge of linear algebra (as it is part of a series).

Reliability 9/10

💬 Très positif. Sur les 30 commentaires analysés, les spectateurs expriment une gratitude immense et une admiration pour la clarté pédagogique, certains mentionnant que la vidéo a transformé leur compréhension de l'algèbre linéaire.