man sin () - sine function

NAME

sin, sinf, sinl - sine function

SYNOPSIS

#include <math.h>

double sin(double x);

float sinf(float x);

long double sinl(long double x);

DESCRIPTION

These functions shall compute the sine of their argument x, measured in radians.

An application wishing to check for error situations should set errno to zero and call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if errno is non-zero or fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error has occurred.

RETURN VALUE

Upon successful completion, these functions shall return the sine of x.

If x is NaN, a NaN shall be returned.

If x is 0, x shall be returned.

If x is subnormal, a range error may occur and x should be returned.

If x is Inf, a domain error shall occur, and either a NaN (if supported), or an implementation-defined value shall be returned.

ERRORS

These functions shall fail if:

Domain Error
The x argument is Inf.

If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then errno shall be set to [EDOM]. If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, then the invalid floating-point exception shall be raised.

These functions may fail if:

Range Error
The value of x is subnormal

If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then errno shall be set to [ERANGE]. If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, then the underflow floating-point exception shall be raised.

The following sections are informative.

EXAMPLES

Taking the Sine of a 45-Degree Angle

#include <math.h>
...
double radians = 45.0 * M_PI / 180;
double result;
...
result = sin(radians);



APPLICATION USAGE

These functions may lose accuracy when their argument is near a multiple
of pi or is far
from 0.0.


On error, the expressions (math_errhandling & MATH_ERRNO) and (math_errhandling
& MATH_ERREXCEPT) are independent of
each other, but at least one of them must be non-zero.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

asin() , feclearexcept() , fetestexcept() , isnan()
, the Base Definitions volume of
IEEE Std 1003.1-2001, Section 4.18, Treatment of Error Conditions
for
Mathematical Functions, <math.h>

COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .