(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Not so much a problem, just an error I noticed... It's in the third edition (and update of the third edition) of David C. Lay's Linear Algebra and its Applications.

2. Relevant equations

p.228, last sentence:

"Every linear combination of u, v, and w is an element of Nul A. Thus, {u, v, w} is a spanning set for Nul A."

3. The attempt at a solution

The "thus" is incorrect--I think what he's trying to say is that every element of Nul A is a linear combination of u, v and w. Thus, {u, v, w} is a spanning set for Nul A.

As stated, I think it is false.

For instance, take this case:

Given: {u, v, w} is a basis for Nul A

Superimpose his statement:

Every linear combination of u and v is an element of Nul A.

Thus, {u, v} is a spanning set for Nul A. (--><--) (contradiction).

I found this while doing the reading for class several weeks back. I looked online and I couldn't find any errata for this book--does anyone know of any other errors in the book? Anyone disagree that this is incorrect, or at least unclear?

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# Homework Help: Error on p228 Of D.Lay's Linear Algebra

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