Тригонометрия. Формулы. Шпарга

This application is a free reference book of trigonometric formulas or trigonometric identities that describe the dependencies between sine, cosine, tangent and cotangent and are used in solving mathematical problems.

The appendix contains basic trigonometric identities (equalities), lower degree formulas, double angle formulas, cosine of a double angle, sine of a double angle, and other formulas. Additionally, the values ​​of trigonometric functions for the most common angles are given.