Trigonometry

Trigonometry is a branch of mathematics concerned with relationships between angles and side lengths of triangles. In particular, the trigonometric functions relate the angles of a right triangle with ratios of its side lengths. The field emerged in the Hellenistic world during the 3rd century BC from applications of geometry to astronomical studies.

The Greeks focused on the calculation of chords, while mathematicians in India created the earliest-known tables of values for trigonometric ratios such as sine.

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Source: Wikipedia · Image: Wikimedia Commons · CC BY-SA 3.0

SINCOSTAN

Trigonometry that clicks — calculators, identities, and worked explanations for angles and waves.

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