sin

sin

Compute the Trigonometric Sine

Portability: ISO/ANSI C conforming, UNIX compatible

SYNOPSIS
DESCRIPTION
RETURN VALUE
DIAGNOSTICS
EXAMPLE
RELATED FUNCTIONS
SEE ALSO

SYNOPSIS

#include <math.h>

double sin(double x);

DESCRIPTION

sin computes the trigonometric sine of its argument x expressed in radians. Because the sine function is periodic, only the value of x mod 2 [pi] is used to compute the sine. If x is very large, only a limited precision is left to represent x mod 2 [pi] . Thus, an error message is written for very large negative or positive arguments (see DIAGNOSTICS).

RETURN VALUE

sin returns the principal value of the sine of the argument x , if this value is defined and computable. The return value is of type double .

DIAGNOSTICS

For a very large argument ( x > 6.7465e9), the function returns 0.0. In this case, the message "total loss of significance" is also written to stderr (the standard error file).

If an error occurs in sin , the _matherr routine is called. You can supply your own version of _matherr to suppress the diagnostic message or modify the value returned.

EXAMPLE

This example computes the trigonometric cosecant of a value:

#include <stdio.h>
#include <math.h>

#define SVECTOR .7854

main()
{
   double cosec;

      /* The cosecant of a value is 1 divided */
      /*  by the sine.                        */
   cosec = 1 / sin(SVECTOR);
   printf("1 / sin(%f) = %f\n", SVECTOR, cosec);
}

RELATED FUNCTIONS

cos , _matherr , tan

SEE ALSO

Mathematical Functions

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