
tan(+Number, -Result)
-Result is tan(+Number)

   Evaluates the trigonometric function tan(Number) and unifies the resulting
value with Result.



Arguments
   Number              A number.
   Result              Output: float or breal.

Type
   Arithmetic

Description

   Evaluates the trigonometric function tan(Number) and unifies the resulting
   value with Result.

   This predicate can be used as a function in arithmetic expressions.
   In coroutining mode, if Number is uninstantiated, the call to tan/2 is
   delayed until this variable is instantiated.




Modes and Determinism
   tan(+, -) is det

Exceptions
     4 --- Number is not instantiated (non-coroutining mode only).
    24 --- Number is not of a numeric type.
    20 --- Illegal arithmetic operation:  Number is (2k +1) * pi/2 for    every integer k.

Examples
   
Success:
    Result is tan(0).		% gives Result = 0.0
    Result is tan(12.3).        % gives Result = -0.272854
    Result is tan(-1).          % gives Result = -1.55741

Error:
    X is pi/2, tan(X). 		% arithmetic exception


See Also
   is / 2
