arccosny
The term "arccosny" does not correspond to a recognized mathematical function, concept, or standard abbreviation within established mathematical literature or common usage. It is possible that "arccosny" is a typographical error, a misspelling of a related term, or a specific identifier within a non-standard context.
The function "arccos" itself is the inverse cosine function, also known as the inverse trigonometric function
If "arccosny" is intended to represent a modification or extension of the arccos function, further clarification