TRIG(3M)            UNIX Programmer's Manual             TRIG(3M)

NAME
     sin, cos, tan, asin, acos, atan, atan2 - trigonometric func-
     tions

SYNOPSIS
     #include <math.h>

     double sin (x)
     double x;

     double cos (x)
     double x;

     double tan (x)
     double x;

     double asin (x)
     double x;

     double acos (x)
     double x;

     double atan (x)
     double x;

     double atan2 (y, x)
     double x, y;

HP-UX COMPATIBILITY
     Level:    HP-UX/RUN ONLY

     Origin:   System III

DESCRIPTION
     _S_i_n, _c_o_s and _t_a_n return trigonometric  functions  of  radian
     arguments.   The magnitude of the argument should be checked
     by the caller to make sure the result is meaningful.

     _A_s_i_n returns the arc sine in the range -pi/2 to pi/2.

     _A_c_o_s returns the arc cosine in the range 0 to pi.

     _A_t_a_n returns the arc tangent of _x  in  the  range  -pi/2  to
     pi/2.

     _A_t_a_n_2 returns the arc tangent of _y/_x in the range -pi to pi.

HARDWARE DEPENDENCIES
     Series 200/500:
          The approximate limit for the values returned by  these
          functions is 1.49^8.

          The algorithms used for all functions except _a_t_a_n_2  are
          from HP 9000 BASIC.

DIAGNOSTICS
     Arguments of magnitude greater than 1 cause _a_s_i_n and _a_c_o_s to
     return value 0.

     For _s_i_n, _c_o_s, _t_a_n, if the argument is out of range of  accu-
     rate  calculations,  _e_r_r_n_o  is  set  to  EDOM  and  zero  is
     returned.