mathman said:Have you tried Google?
The most common locations to find proofs of trigonometric identities are in textbooks, online resources, math forums, and academic journals.
Yes, there are many websites and resources that specialize in providing proofs of trigonometric identities, such as MathWorld, Khan Academy, and Wolfram MathWorld. These websites often have a comprehensive collection of proofs for various trigonometric identities.
One way to verify the correctness of a proof for a trigonometric identity is to follow each step and check if it is mathematically valid. Additionally, you can compare the proof to other existing proofs for the same identity and see if they follow similar logic.
Yes, you can use trigonometric identities without knowing their proofs. However, understanding the proofs can help you better understand the relationships between different trigonometric functions and how they can be manipulated to solve equations or simplify expressions.
No, it is not necessary to memorize proofs of trigonometric identities. It is more important to understand the concepts and logic behind the proofs in order to apply them in problem-solving situations.