USEFUL TRIGONOMETRIC IDENTITIES Sums and di erences of angles cos(A + B) = cos A cos B sin A sin B cos(A B) = cos A cos B + sin A sin B sin(A + B) = sin A cos B + cos A sin B sin(A B) = sin A cos B cos A sin B ** See other side for more identities **
Trigonometry - MathGuy. US 1 tan Product‐to‐Sum Formulas Triple Angle Formulas Power Reducing Formulas Arc Length Law of Sines
Chapter 7: Trigonometric Equations and Identities Chapter 7: Trigonometric Equations and Identities In the last two chapters we have used basic definitions and relationships to simplify trigonometric expressions and equations In this chapter we will look at more complex relationships that allow us to consider combining and composing equations By conducting a deeper study of the trigonometric identities we can learn to simplify expressions