tan() computes the tangent of x, measured in radians.

    tand() computes the tangent of x, measured in degrees.

                           Entry-Point Names

    Generic                               Compaq
    Function   Data Type   OpenVMS        Tru64 UNIX
    Name       Required    Alpha          Alpha

    tan        S_FLOAT     math$tan_s     tanf
               T_FLOAT     math$tan_t     tan
               X_FLOAT     math$tan_x     tanl
               F_FLOAT     math$tan_f
               G_FLOAT     math$tan_g

    tand       S_FLOAT     math$tand_s    tandf
               T_FLOAT     math$tand_t    tand
               X_FLOAT     math$tand_x    tandl
               F_FLOAT     math$tand_f
               G_FLOAT     math$tand_g