When comparing A First Course in Linear Algebra vs Lemma: Linear Algebra, the Slant community recommends A First Course in Linear Algebra for most people. In the question“What are the best resources to learn linear algebra?” A First Course in Linear Algebra is ranked 6th while Lemma: Linear Algebra is ranked 7th.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Rich practice in Khan Academy style
For every lesson, it has a "worksheet" where you can attempt to solve problems in the set. And for each problem, there's a "check" button where you can see if it's right or not, and also there're "hint" and "solutions" for each problem.
The website also uses the "smart textbox" for entering equations conveniently like what Khan academy does.
Pro Very well completed in content
Explicit in content for pretty much everything you need to learn about Linear algebra.
Cons
Con Too much "Polynomial vectors"
He's mixing too much things out of core ideas of Linear algebra, which leads to confusion.