Evaluate using the Sum and Difference Formulas

The video tutorial covers the cosine addition formula, demonstrating how to apply it to specific angles. The instructor explains the calculations for cosine and sine in different quadrants and discusses factoring techniques in trigonometric expressions. The session concludes with a reflection on teaching methods and approaches to help students understand the material better.

What is the formula for the cosine of the sum of two angles?

How does the cosine of 120 degrees relate to its position in the unit circle?

Explain the significance of the second quadrant in trigonometric functions.

What happens to the sine value in the second quadrant?

How can you factor out common terms in trigonometric expressions?