👉 In the context of mathematics, "retsinas" refers to a trigonometric function. It is one of the six fundamental trigonometric functions (the others being sine, cosine, tangent, cotangent, secant, and cosecant). The name "retsinas" comes from Latin, meaning "return," as it represents a return or return period. The retsinas are related to other trigonometric functions in that they all involve angles whose measures are not precisely known but