IEEE Std 1003.1-2008

Copyright © 2001-2008 The IEEE and The Open Group

sin, sinf, sinl - sine function

#include <math.h>

double sin(doublex);

float sinf(floatx);

long double sinl(long doublex);

^{[CX]}The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2008 defers to the ISO C standard.These functions shall compute the sine of their argument

x, measured in radians.An application wishing to check for error situations should set

errnoto zero and callfeclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, iferrnois non-zero orfetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error has occurred.

Upon successful completion, these functions shall return the sine of

x.

^{[MX]}Ifxis NaN, a NaN shall be returned.If

xis ±0,xshall be returned.If

xis subnormal, a range error may occur andxshould be returned.If

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

These functions shall fail if:

- Domain Error
^{[MX]}Thexargument is ±Inf.If the integer expression (

math_errhandling& MATH_ERRNO) is non-zero, thenerrnoshall 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
^{[MX]}The value ofxis subnormalIf the integer expression (

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

## Taking the Sine of a 45-Degree Angle

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

These functions may lose accuracy when their argument is near a multiple of 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.

None.

None.

asin,feclearexcept,fetestexcept,isnanXBD

Treatment of Error Conditions for Mathematical Functions,<math.h>

First released in Issue 1. Derived from Issue 1 of the SVID.

The last two paragraphs of the DESCRIPTION were included as APPLICATION USAGE notes in previous issues.

The

sinf() andsinl() functions are added for alignment with the ISO/IEC 9899:1999 standard.The DESCRIPTION, RETURN VALUE, ERRORS, and APPLICATION USAGE sections are revised to align with the ISO/IEC 9899:1999 standard.

IEC 60559:1989 standard floating-point extensions over the ISO/IEC 9899:1999 standard are marked.

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