Precalculus with Unit-Circle Trigonometry by David Cohen is a comprehensive textbook that covers all the essential topics in precalculus, with a focus on developing students’ understanding of trigonometry using the unit circle. The book includes clear explanations, detailed examples, and numerous practice problems to help students master the concepts. One of the key benefits of using this textbook is its emphasis on connecting trigonometry to the unit circle, which helps students develop a deeper understanding of the subject. Additionally, the book covers a wide range of topics, from functions and graphs to complex numbers and vectors, making it a versatile resource for precalculus students. To use Precalculus with Unit-Circle Trigonometry effectively, students should carefully read and understand the explanations in each section, work through the examples to see how the concepts are applied, and practice solving the problems to reinforce their understanding. Regular practice and review of the material will help students build a strong foundation in precalculus and trigonometry.