asin, asinf, asinl
| Defined in header <math.h>
|
||
| float asinf( float arg ); |
(1) | (since C99) |
| double asin( double arg ); |
(2) | |
| long double asinl( long double arg ); |
(3) | (since C99) |
| Defined in header <tgmath.h>
|
||
| #define asin( arg ) |
(4) | (since C99) |
1-3) Computes the principal values of the arc sine of
arg.4) Type-generic macro: If the argument has type long double,
asinl is called. Otherwise, if the argument has integer type or the type double, asin is called. Otherwise, asinf is called. If the argument is complex, then the macro invokes the corresponding complex function (casinf, casin, casinl).Parameters
| arg | - | floating point value |
Return value
If no errors occur, the arc sine ofarg (arcsin(arg)) in the range [-| π |
| 2 |
| π |
| 2 |
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.
Domain error occurs if arg is outside the range [-1.0; 1.0].
If the implementation supports IEEE floating-point arithmetic (IEC 60559),
- If the argument is ±0, it is returned unmodified
- If |arg| > 1, a domain error occurs and NaN is returned.
- if the argument is NaN, NaN is returned
Example
Run this code
#include <math.h> #include <stdio.h> #include <errno.h> #include <fenv.h> #include <string.h> #pragma STDC FENV_ACCESS ON 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"); }
Possible output:
asin( 1.0) = +1.570796, 2*asin( 1.0)=+3.141593
asin(-0.5) = -0.523599, 6*asin(-0.5)=-3.141593
asin(0.0) = 0.000000, asin(-0.0)=-0.000000
asin(1.1) = nan
errno == EDOM: Numerical argument out of domain
FE_INVALID raisedReferences
- C11 standard (ISO/IEC 9899:2011):
- 7.12.4.2 The asin functions (p: 238)
- 7.25 Type-generic math <tgmath.h> (p: 373-375)
- F.10.1.2 The asin functions (p: 518)
- C99 standard (ISO/IEC 9899:1999):
- 7.12.4.2 The asin functions (p: 219)
- 7.22 Type-generic math <tgmath.h> (p: 335-337)
- F.9.1.2 The asin functions (p: 456)
- C89/C90 standard (ISO/IEC 9899:1990):
- 4.5.2.2 The asin function
See also
| (C99)(C99) |
computes arc cosine (arccos(x)) (function) |
| (C99)(C99) |
computes arc tangent (arctan(x)) (function) |
| (C99)(C99) |
computes arc tangent, using signs to determine quadrants (function) |
| (C99)(C99) |
computes sine (sin(x)) (function) |
| (C99)(C99)(C99) |
computes the complex arc sine (function) |