Section 11,84: TAN

 TAN (real-number)

 A function that returns the tangent of the argument.  The argument
 must be in radians; it is treated modulo 2*pi.
 +------+---------+----------+------------+-------------+        
 | Args | Generic | Specific |  Argument  | Result Type |
 +------+---------+----------+------------+-------------+
 |  1   |  TAN    | TAN      | REAL*4     | REAL*4      |
 |      |         | DTAN     | REAL*8     | REAL*8      |
 |      |see note | QTAN     | REAL*16    | REAL*16     |
 +------+---------+----------+------------+-------------+

 NOTE: QTAN is not available in DEC Fortran.