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## Advanced Trig Formulas

Summary

The content provides an in-depth exploration of advanced trigonometry formulas crucial for tackling GRE exam questions, emphasizing the importance of familiarity rather than memorization.

- Introduction to sign rules and their implications for graph shapes, highlighting the differences between sine and cosine in relation to the unit circle.
- Explanation of angle addition and subtraction rules, including the derivation of sine and cosine values for specific angles through the use of special triangles.
- Presentation of practice problems to apply the discussed formulas, reinforcing the concept that understanding and familiarity with these formulas are more critical than memorization.
- Discussion on formulas for non-right triangles, specifically the Law of Cosines and the Law of Sines, and how they extend the Pythagorean theorem to apply to any triangle.
- Guidance on solving geometry problems on the GRE by practicing with these formulas to become comfortable with their application, even if they are not memorized.

Chapters

00:31

Sign Rules and Graph Implications

02:00

Angle Addition and Subtraction Rules

03:08

Practice Problem: Angle Addition

04:52

Formulas for Non-Right Triangles