NAME

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

SYNOPSIS

cc [flag . . . ] file . . .  −lm [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).

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. 

  —  Math Libraries