Trigonometric Formulas: Addition and Subtraction

This lecture delves into trigonometric formulas, focusing on addition and subtraction. The instructor explains the derivation of addition formulas and demonstrates how they lead to double angle formulas and angle transformation formulas. By using geometric ideas and rotation matrices, the lecture simplifies the process of obtaining trigonometric identities. Through detailed examples, the audience learns how to apply these formulas to calculate trigonometric values efficiently. The lecture also covers strategies for tackling complex trigonometric equations, emphasizing the importance of precise angle localization and the use of known trigonometric values to simplify calculations.