Functions defined in terms of a right-angled triangle (see diagram) and widely used in the solution of many mathematical problems. They are defined as:
tangent of angle A, written tanA = a/b
sine of angle A, written sinA = a/c
cosine of angle A, written cosA = b/c,
where a is the length of the side opposite the angle A, b is the length of the side opposite the angle B, and c is the hypotenuse of the triangle. The reciprocal functions are:
cotangent of angle A, written cotA = 1/tanA = b/a
secant of angle A, written secA = 1/cosA = c/b
cosecant of angle A, written cosecA = 1/sinA = c/a
Trigonometric functions
- thermodynamics
- thermoelectricity
- thermograph
- thermography
- thermoluminescence
- thermoluminescent dating
- thermometer
- thermonuclear reaction
- thermonuclear reactor
- thermonuclear weapon
- thermopile
- thermostat
- theta vacuum
- thixotropy
- Thompson, Benjamin
- Thomson effect
- Thomson scattering
- Thomson, Sir Joseph, John
- Thomson, Sir William
- thorium
- thorium series
- three-body problem
- threshold
- threshold frequency
- thrust