sin, sinf, sinl

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< c ‎ | numeric ‎ | math
Common mathematical functions
Types
Functions
Basic operations
(C99)
(C99)
(C99)
(C99) (C99) (C99) (C23)
Maximum/minimum operations
Exponential functions
Power functions
Trigonometric and hyperbolic functions
Error and gamma functions
(C99)
(C99)
(C99)
(C99)
Nearest integer floating-point operations
(C99) (C99) (C99)
(C23) (C23) (C23) (C23)
Floating-point manipulation functions
Narrowing operations
(C23)
(C23)
(C23)
(C23)
(C23)
(C23)
Quantum and quantum exponent functions
Decimal re-encoding functions
Total order and payload functions
Classification
Macro constants
Special floating-point values
Arguments and return values
Error handling
Defined in header <math.h>
float sinf ( float arg ) ;
(1) (since C99)
double sin ( double arg ) ;
(2)
long double sinl ( long double arg ) ;
(3) (since C99)
_Decimal32  sind32 ( _Decimal32 arg ) ;
(4) (since C23)
_Decimal64  sind64 ( _Decimal64 arg ) ;
(5) (since C23)
_Decimal128 sind128 ( _Decimal128 arg ) ;
(6) (since C23)
Defined in header <tgmath.h>
#define sin( arg )
(7) (since C99)
1-3) Computes the sine of arg (measured in radians).
7) Type-generic macro: If the argument has type long double , (3) ( sinl ) is called. Otherwise, if the argument has integer type or the type double , (2) ( sin ) is called. Otherwise, (1) ( sinf ) is called. If the argument is complex, then the macro invokes the corresponding complex function ( csinl , csin , csinf ).

The functions (4-6) are declared if and only if the implementation predefines __STDC_IEC_60559_DFP__ (i.e. the implementation supports decimal floating-point numbers).

(since C23)

Parameters

arg - floating-point value representing an angle in radians

Return value

If no errors occur, the sine of arg ( sin(arg) ) in the range [-1 ; +1] , is returned.

The result may have little or no significance if the magnitude of arg is large.

(until C99)

If a domain error occurs, an implementation-defined value is returned (NaN where supported).

If a range error occurs due to underflow, the correct result (after rounding) is returned.

Error handling

Errors are reported as specified in math_errhandling .

If the implementation supports IEEE floating-point arithmetic (IEC 60559):

  • if the argument is ±0, it is returned unmodified;
  • if the argument is ±∞, NaN is returned and FE_INVALID is raised;
  • if the argument is NaN, NaN is returned.

Notes

The case where the argument is infinite is not specified to be a domain error in C, but it is defined as a domain error in POSIX .

POSIX also specifies that in case of underflow, arg is returned unmodified, and if that is not supported, an implementation-defined value no greater than DBL_MIN , FLT_MIN , and LDBL_MIN is returned.

Example

#include <errno.h>
#include <fenv.h>
#include <math.h>
#include <stdio.h>
 
#ifndef __GNUC__
#pragma STDC FENV_ACCESS ON
#endif
 
int main(void)
{
    const double pi = acos(-1);
 
    // typical usage
    printf("sin(pi/6) = %f\n", sin(pi / 6));
    printf("sin(pi/2) = %f\n", sin(pi / 2));
    printf("sin(-3*pi/4) = %f\n", sin(-3 * pi / 4));
 
    // special values
    printf("sin(+0) = %f\n", sin(0.0));
    printf("sin(-0) = %f\n", sin(-0.0));
 
    // error handling
    feclearexcept(FE_ALL_EXCEPT);
    printf("sin(INFINITY) = %f\n", sin(INFINITY));
    if (fetestexcept(FE_INVALID))
        puts("    FE_INVALID raised");
}

Possible output:

sin(pi/6) = 0.500000
sin(pi/2) = 1.000000
sin(-3*pi/4) = -0.707107
sin(+0) = 0.000000
sin(-0) = -0.000000
sin(INFINITY) = -nan
    FE_INVALID raised

References

  • C23 standard (ISO/IEC 9899:2024):
  • 7.12.4.6 The sin functions (p: TBD)
  • 7.27 Type-generic math <tgmath.h> (p: TBD)
  • F.10.1.6 The sin functions (p: TBD)
  • C17 standard (ISO/IEC 9899:2018):
  • 7.12.4.6 The sin functions (p: 175)
  • 7.25 Type-generic math <tgmath.h> (p: 272-273)
  • F.10.1.6 The sin functions (p: 378)
  • C11 standard (ISO/IEC 9899:2011):
  • 7.12.4.6 The sin functions (p: 239-240)
  • 7.25 Type-generic math <tgmath.h> (p: 373-375)
  • F.10.1.6 The sin functions (p: 519)
  • C99 standard (ISO/IEC 9899:1999):
  • 7.12.4.6 The sin functions (p: 220)
  • 7.22 Type-generic math <tgmath.h> (p: 335-337)
  • F.9.1.6 The sin functions (p: 456)
  • C89/C90 standard (ISO/IEC 9899:1990):
  • 4.5.2.6 The sin function

See also

(C99) (C99)
computes cosine ( cos(x) )
(function)
(C99) (C99)
computes tangent ( tan(x) )
(function)
(C99) (C99)
computes arc sine ( arcsin(x) )
(function)
(C99) (C99) (C99)
computes the complex sine
(function)