The trigonometric ratios sine, cosine and tangent are associated with the right triangle and the relationships between the legs and the hypotenuse. These relationships are constituted according to the following reasons:
sine
cosine
tangent
These trigonometric ratios have inverses that are named cosecant, secant and cotangent.
The inverse of sine is the cosecant (cossec). 
The inverse of the cosine is the secant (sec). 
The inverse of the tangent is the cotangent (cotg). 
The inverse ratios of sine, cosine and tangent can be represented by the following expressions:
cosecant
drying
cotangent
Knowledge of trigonometric ratios and their inverses will help in studies related to relationships fundamentals between the functions of the same arc, derived relations and the development of identities trigonometric.
by Mark Noah
Graduated in Mathematics
Brazil School Team
Trigonometry - Math - Brazil School
Source: Brazil School - https://brasilescola.uol.com.br/matematica/as-razoes-inversas-seno-cosseno-tangente.htm