Sections 2.4 Sum and Difference Formulas

Section Objectives

  1. Use sum and difference formulas to evaluate trigonometric functions.
  2. Use sum and difference formulas to verify trigonometric identities.
  3. Use sum and difference formulas to solve trigonometric equations.



Sum and Difference Formulas

There are six common sum and difference formulas. Here they are written in compact form:



Examples for Objective 1










Examples for Objective 2










Examples for Objective 3