angle addition formulas

The trigonometric addition formulas are a set of formulas that express trigonometric functions of sums of angles in terms of the trigonometric functions of the original angles.

Angle addition formulas express trigonometric functions of sums of angles α ± β in terms of functions of α and β. The fundamental formulas of angle addition in trigonometry are given by sin(α + β) | = | sin α cos β + sin β cos α sin(α - β) | = | sin α cos β - sin β cos α cos(α + β) | = | cos α cos β - sin α sin β cos(α - β) | = | cos α cos β + sin α sin β tan(α + β) | = | (tan α + tan β)/(1 - tan α tan β) tan(α - β) | = | (tan α - tan β)/(1 + tan α tan β).

double-angle formulas | half-angle formulas | harmonic addition theorem | multiple-angle formulas | prosthaphaeresis formulas | trigonometry | trigonometry angles | Werner formulas

high school level (California trigonometry standard)