sin, sinf, sinl - sine function
double sin(double x);
float sinf(float x);
long double sinl(long double x);
[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 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.
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 subnormal, a range error may occur
[MXX] and x should be returned.
[MX] 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.
If x is ±Inf, a domain error shall occur, and a NaN shall be returned.
These functions shall fail if:
- Domain Error
- [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:
- Range Error
- [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.
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.
asin, feclearexcept, fetestexcept, isnan
XBD 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() and sinl() 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.
POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0585  and XSH/TC1-2008/0586  are applied.
return to top of page