Sum and Difference Identities – Formulas and Examples

The sum and difference identities of angles are trigonometric identities used to calculate the values of certain angles. These identities … Read more

Half-angle identities – Formulas, proof and examples

Half-angle identities are trigonometric identities used to simplify trigonometric expressions and calculate the sine, cosine, or tangent of half-angles when … Read more

Double Angle Identities – Formulas, Proof and Examples

Double angle identities are trigonometric identities used to rewrite trigonometric functions, such as sine, cosine, and tangent, that have a … Read more

Fundamental Trigonometric Identities

Trigonometric identities are equations, which are true for any angle used. Trigonometric identities are used to rewrite trigonometric expressions and … Read more

Formulas for the Trigonometric Identities

Trigonometric identities are useful when we want to rewrite or simplify trigonometric expressions. Trigonometric identities are true for every value … Read more

Quotient Identities – Formulas and Examples

Quotient identities are trigonometric identities that are written as fractions of the sine and cosine functions. The tangent forms a … Read more

Reciprocal Identities – Formulas and examples

We have already become familiar with the trigonometric functions of sine, cosine, and tangent. These functions are written as fractions … Read more

Pythagorean Identities – Formulas, Proof and Examples

Pythagorean identities are identities in trigonometry that are extensions of the Pythagorean theorem. Pythagorean identities are useful for simplifying trigonometric … Read more

Law of Sines and Cosines – Formulas and Examples

The laws of sine and cosine are relations that allow us to find the length of one side of a … Read more

Law of Cosines – Examples and Practice Problems

The law of cosines is an equation that relates the lengths of two sides of a triangle and their intermediate … Read more