VMS Help FORTRAN, Intrinsic Procedures, TAN  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  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      |
  |      |         | QTAN     | REAL*16    | REAL*16     |
  +------+---------+----------+------------+-------------+