In the section in Interactive Linear Algebra about Least Squares(the ellipse) I believe the RREF calculations is not correct.
The textbooko says the RREF form is
[[1,0,0,0,0,405/266],
[0,1,0,0,0,−89/133],
[0,0,1,0,0,201/133],
[0,0,0,1,0,−123/266],
[0,0,0,0,1,−687/133]]

But I believe it should be

[['1' '0' '0' '0' '0' '10355/8574'],
['0' '1' '0' '0' '0' '-102/1429'],
['0' '0' '1' '0' '0' '1623/1429'],
['0' '0' '0' '1' '0' '-2499/2858'],
['0' '0' '0' '0' '1' '-20113/4287']]

I have gotten this answer through multiple methods including, using my own code, using rref calculators online and using sympy.

https://textbooks.math.gatech.edu/ila/chap-algebra.html

you will see hnow to express all solutions of a system of linear equations in a unique way using the parametric form of the general solution.

In 3.5.4 Invertible linear transformations, several non-linear transformations (e.g. f(x) = x^3) were used to illustrate non-invertible transformations. It seems to me that since they are not linear to begin with, it's not very educational to use them in a section on invertible linear transformations. (A transformation that's non-linear is not, by definition, an invertible linear transformation.)

At the very least, the section should mention they are not linear to begin with, but are used anyway to illustrate the invertibility aspect alone.

This line reads ... If <m>V</m> is the zero subspace, then it is the span of the empty set.... Should it read then it is the span of the zero vector, since a subspace cannot be empty?

Even though a few pages later the book states "It is natural to define Span{} = {0}," at the line above this was not yet established.

In the very first equation of this section (4.3), following "The paralellepiped determined by n vectors", the vectors themselves are introduced as a set of V_i, but the equation (slightly below) uses a set of X_i.

There is a typing error in Example(A nonstandard coordinate system on R^2.
"Using this grid it is easy to see that the B-coordinates of v are (5 1)".
The number 5 should be 4 in context.

In reference to version 9aac2a9

Eigenspaces section.
"then λ is not an eigenvector of A. " should be "then λ is not an eigenvalue of A ."

In reference to version 9aac2a9

Equatiion -> Equation

\Nul(A^TA)=0 -> \Nul(A^TA)={0}

It should be "linear dependence".

In Example 2.4.17 of chapter "Solution Sets"

The solution to Ax = b is: span{ (1, 1, 0), (-2, 0, 1) } + p, instead of span{ (1, 1, 1), (-2, 0, 1) } + p where p is the particular solution.

In "Recipe: a 2 x 2 matrix with complex eigenvalues" #3 it says "Find a corresponding (complex) eigenvalue v using the trick." It should say eigenvector.

z any real number -> z is any real number

Hey, don't know if this is the right place but I just wanted to thank all the people involved in this amazing book, it's truly a pleasure to read. The concepts become so clear with all these amazing graphics, tikz pictures and even MathBox interactivity. So much work must have gone into it from conceptualization to graphics, nice explanations and customaization of PreTeXt. Thank you for all your effors, it really pays off for the readers and I wish more books like this one were out there.

Problem description

There's a link "Comments, corrections or suggestions?" at the footer in each page, and the link points to the archived repository QBobWatson/gt-linalg. Since the repository has been archived, no new issues can be created and consequently the link opens GitHub 404 page.

The following code should have worked but not, maybe it's a deployment-related issue?

In reference to version 9aac2a9

There is an error in the example: The solution set is a plane：

The last-but-one line in the proof of the only fact in the above-mentioned section was intended to say

It follows that $c_i − c'_i = 0$ for all i,

The equals zero-part is currently missing.

BTW, I really like your book!

"If A has n rows, then Ax has m entries."
It should be:
"If A has m rows, then Ax has m entries."