"Trigonometry is a branch of mathematics concerned with relationships between angles and ratios of lengths."
The study of angles and triangles, including trigonometric functions, identities, and applications.
Angles: The measurement of the amount of turn between two lines or rays is called an angle.
Right Triangle Trigonometry: A branch of mathematics which deals with the relationships between the sides and angles of a right triangle.
Trigonometric Functions: Functions of an angle that describe the relationships between the sides and angles in a right triangle.
Sine Function: The ratio of the length of the opposite side to the length of the hypotenuse in a right triangle.
Cosine Function: The ratio of the length of the adjacent side to the length of the hypotenuse in a right triangle.
Tangent Function: The ratio of the length of the opposite side to the length of the adjacent side in a right triangle.
Cosecant Function: The reciprocal of the sine function.
Secant Function: The reciprocal of the cosine function.
Cotangent Function: The reciprocal of the tangent function.
Unit Circle: A circle of radius 1 centered at the origin of a coordinate system, used to visualize the values of trigonometric functions for angles in all quadrants.
Radians and Degrees: Units of measurement for angles.
Inverse Trigonometric Functions: Functions which find the angle given the ratio of the sides of a right triangle.
Trigonometric Identities: Equations that are true for all angles, used to simplify trigonometric expressions.
"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."
"Mathematicians in India created the earliest-known tables of values for trigonometric ratios (also called trigonometric functions) such as sine."
"Trigonometry has been applied in areas such as geodesy, surveying, celestial mechanics, and navigation."
"Trigonometry is known for its many identities."
"These trigonometric identities are commonly used for rewriting trigonometrical expressions with the aim to simplify an expression."
"To find a more useful form of an expression."
"To solve an equation."
"From Ancient Greek τρίγωνον (trígōnon) 'triangle' and μέτρον (métron) 'measure'."
"The field emerged in the Hellenistic world during the 3rd century BC."
"Applications of geometry to astronomical studies."
"Tables of values for trigonometric ratios (also called trigonometric functions) such as sine."
"Trigonometry has been applied in geodesy."
"Trigonometry has been applied in surveying."
"Trigonometry has been applied in celestial mechanics."
"Trigonometry has been applied in navigation."
"Trigonometry is known for its many identities."
"To simplify an expression."
"To find a more useful form of an expression or to solve an equation."