The TAN function returns a value that approximates the tangent of an angle or arc, expressed in radians, that is specified
by argument-1. The type of this function is numeric.

- Argument-1 must be class numeric.
Note: Conversion factors from degrees and Gon (grad) to radians are specified in the section Trigonometric Functions.

- The returned value is the approximation of the tangent of argument-1.
- Floating-point format is used for numeric non-integer results.