Trigonometry (Coburn), 1st Edition

Section 4: Double Angle, Half Angle, and Product-to-Sum identities

A. Derive and use the doubleangle identities for cosine, tangent, and sine
B. Develop and use the power reduction and half-angle identities
C. Derive and use the productto-sum and sum-to-product identities
D. Solve applications using these identities