https://d2l.ai/chapter_appendix-mathematics-for-deep-learning/eigendecomposition.html
This is a very minor issue, but in 22.2.6.2 at the very end "If we look at the last portion of the above computation, we see that the random vector is stretched by a factor of 1.974459321485[...],
I think the number 1.97 is a typo at should be 2.45 as that is the largest eigenvalue as well as the number the chart suggests
Section 22.2.4
we may take W to be an orthogonal matrix orthonormal matrix —a matrix whose columns are all length one vectors that are at right angles to one another,
Section 22.2.62
If we look at the last portion of the above computation, we see that the random vector is stretched by a factor of 1.974459321485 2.4532[...] , where the portion at the end shifts a little, but the stretching factor is stable.