asin, asinf, asinl

Header: <math.h>

1-6) Computes the principal values of the arc sine of arg.

# Declarations

float asinf( float arg );

(since C99)

double asin( double arg );

long double asinl( long double arg );

(since C99)

_Decimal32 asind32( _Decimal32 arg );

(since C23)

_Decimal64 asind64( _Decimal64 arg );

(since C23)

_Decimal128 asind128( _Decimal128 arg );

(since C23)

#define asin( arg )

(since C99)

# Parameters

# Return value

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

# Example

#include <errno.h>
#include <fenv.h>
#include <math.h>
#include <stdio.h>
#include <string.h>
 
#ifndef __GNUC__
#pragma STDC FENV_ACCESS ON
#endif
 
int main(void)
{
    printf("asin( 1.0) = %+f, 2*asin( 1.0)=%+f\n", asin(1), 2 * asin(1));
    printf("asin(-0.5) = %+f, 6*asin(-0.5)=%+f\n", asin(-0.5), 6 * asin(-0.5));
 
    // special values
    printf("asin(0.0) = %1f, asin(-0.0)=%f\n", asin(+0.0), asin(-0.0));
 
    // error handling
    errno = 0; feclearexcept(FE_ALL_EXCEPT);
    printf("asin(1.1) = %f\n", asin(1.1));
    if (errno == EDOM)
        perror("    errno == EDOM");
    if (fetestexcept(FE_INVALID))
        puts("    FE_INVALID raised");
}

# See also