TAN()
TAN() — Returns the tangent of an angle specified in radians.
Synopsis
TAN(  {numeric-expression}  ) 
Description
The TAN() function returns the tangent of a specified angle as a FLOAT value. The angle must be specified in radians
    as a numeric expression.
Example
The following example returns the sine, cosine, and tangent of angles from 0 to 90 degrees (where the angle is
    specified in radians).