The discussion centers on the need for effective self-study resources in trigonometry, particularly for someone who has forgotten much of what they learned in high school. A highly recommended book is "Trigonometry" by Gelfand, noted for its creative problems and proofs. Another mentioned resource is the Larson & Hostetler Trigonometry book, which has valuable content but presents challenges in understanding vectors and their operations, such as projections, dot products, and cross products. There is a query about whether these topics are inherently difficult or if the book is lacking in clarity. Additionally, a suggestion is made that a linear algebra book might be more suitable for learning about vectors and related concepts.
