3.2 Sum and Difference Formulas

OpenStax Precalculus 2e — Chapter 7, Section 7.2

Learning Objectives

  • State the sum and difference formulas for sine, cosine, and tangent

  • Use sum/difference formulas to find exact values (e.g., \(\cos 75^\circ\))

  • Verify identities using sum and difference formulas

  • Derive the cofunction identities from the difference formulas

Key Concepts

To be filled during study.

Practice Problems

To be completed with textbook exercises.

Section Summary

To be written after completing the section.

Study Notes

Personal observations and connections to engineering work.