trig(3M)              MATHEMATICAL LIBRARY               trig(3M)



NAME
     trig: sin, sinf, cos, cosf, tan, tanf,  asin,  asinf,  acos,
     acosf, atan, atanf, atan2, atan2f - trigonometric functions

SYNOPSIS
     cc [flag ...] file ...  -lm [library ...]

     cc -O -Ksd [flag ...] file ...  -J sfm [library ...]

     #include <math.h>

     double sin (double x);

     float sinf (float x);

     double cos (double x);

     float cosf (float x);

     double tan (double x);

     float tanf (float x);

     double asin (double x);

     float asinf (float x);

     double acos (double x);

     float acosf (float x);

     double atan (double x);

     float atanf (float x);

     double atan2 (double y, double x);

     float atan2f (float y, float x);

DESCRIPTION
     sin, cos, and tan and the  single-precision  versions  sinf,
     cosf,  and  tanf return, respectively, the sine, cosine, and
     tangent of their argument, x, measured in radians.

     asin and asinf  return  the  arcsine  of  x,  in  the  range
     [-π/2,+π/2].

     acos and acosf return the  arccosine  of  x,  in  the  range
     [0,+π].

     atan and atanf return the arctangent  of  x,  in  the  range
     (-π/2,+π/2).



                   Last change: Math Libraries                  1

trig(3M)              MATHEMATICAL LIBRARY               trig(3M)



     atan2 and atan2f return the arctangent of y/x, in the  range
     (-π,+π],  using the signs of both arguments to determine the
     quadrant of the return value.

SEE ALSO
     matherr(3M).

DIAGNOSTICS
     If the magnitude of the argument of asin,  asinf,  acos,  or
     acosf  is  greater  than 1, or if both arguments of atan2 or
     atan2f are 0, 0 is returned and errno is set  to  EDOM.   In
     addition,  a  message  indicating DOMAIN error is printed on
     the standard error output.

     Except when  the  -Xc  compilation  option  is  used,  these
     error-handling  procedures  may be changed with the function
     matherr.  When the -Xa or -Xc compilation options are  used,
     no error messages are printed.





































                   Last change: Math Libraries                  2