Csc=cosecant, pronunciation [k? u'si:k？ nt].

Cot = cotangent, pronunciation ['k't? ndnt].

In a right triangle, the ratio of the hypotenuse of an acute angle to its adjacent side (that is, the hypotenuse of angle A is closer to its adjacent side) is called the secant of the acute angle, which is expressed in seconds (angles).

In a right triangle, the ratio of the hypotenuse to the opposite side of an acute angle is represented by csc (angle).

In a right-angled triangle, the ratio of the adjacent right-angled side to the opposite right-angled side of an acute angle is called the cotangent of the acute angle, which is expressed by cot (Angle).

Extended data

The historical development of cotangent

The Syrian astronomer and mathematician Al Albatani (850-929) made a cotangent table with an interval of 1 degree from 0 to 90 degrees around 920.

/kloc-In the middle of the 4th century, Arubo (1393- 1449), a descendant of Genghis Khan, organized large-scale astronomical observation and calculation of mathematical tables. His sine table is accurate to 9 decimal places, and he also made 1 "for the interval between 30 degrees and 45 degrees, and 5 for the interval between 45 degrees and 90 degrees.

The British mathematician and Archbishop of Canterbury, Bravadin (1290- 1349), introduced tangent and cotangent into his trigonometric calculation for the first time.