No. 57 Verifying a Trigonometric Identity by Using a Sum and Difference Formula
No. 60 Verifying a Trigonometric Identity by Using a Sum and Difference Formula
No. 38 Finding the Exact Value of a Trigonometric Function
No. 52 Writing a Trigonometric Expression as an Algebraic Expression
No. 71 Solving a Trigonometric Equation by Using Sum and Difference Formulas