SIN(3) Library Functions Manual SIN(3)

sin sinf sinl — sine function

#include <math.h>

double sin(double x);
float sinf(float x);
long double sinl(long double x);

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.1-2024 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 errno to zero and call (FE_ALL_EXCEPT) before calling these functions. On return, if errno is non-zero or (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] If x is NaN, a NaN shall be returned.

If x is ±0, x shall be returned.

If x is ±Inf, a domain error shall occur, and a NaN shall be returned.

If x is subnormal, x should be returned. [MX] If x is subnormal, a range error may occur and, if x is not returned, sin (), sinf (), and sinl () shall return an implementation-defined value no greater in magnitude than DBL_MIN, FLT_MIN, and LDBL_MIN, respectively.

These functions shall fail if:

[MX] 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:

[MX] 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.

#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 ℼ 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(3), feclearexcept(3), fetestexcept(3), isnan(3)

XBD V1_chap04(7), <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 () and sinl () functions are added for alignment with the ISO/IEC 9899:1999 (“ISO C99”) standard.

The DESCRIPTION, RETURN VALUE, ERRORS, and APPLICATION USAGE sections are revised to align with the ISO/IEC 9899:1999 (“ISO C99”) standard.

IEC 60559:1989 standard floating-point extensions over the ISO/IEC 9899:1999 (“ISO C99”) standard are marked.

POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0585 [68] and XSH/TC1-2008/0586 [320] are applied.

Austin Group Defect 1382 is applied, rearranging the text describing the behavior when x is subnormal to avoid the need for two shading changes.

June 14, 2024 posix.fail