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], is returned.
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
#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 raised
References
- 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 (\({\small\arccos{x} }\)arccos(x)) (function) |
(C99)(C99)
|
computes arc tangent (\({\small\arctan{x} }\)arctan(x)) (function) |
(C99)(C99)
|
computes arc tangent, using signs to determine quadrants (function) |
(C99)(C99)
|
computes sine (\({\small\sin{x} }\)sin(x)) (function) |
(C99)(C99)(C99)
|
computes the complex arc sine (function) |
C++ documentation for asin |
© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/c/numeric/math/asin