asin, asinf, asinl
Calculates the arcsine.
Syntax
double asin( double x );
float asinf ( float x );
long double asinl( long double x );
#define asin(X) // Requires C11 or higher
float asin( float x ); // C++ only
long double asin( long double x ); // C++ only
Parameters
x
Value whose arcsine is to be calculated.
Return value
The asin function returns the arcsine (the inverse sine function) of x in the range -π/2 to π/2 radians.
By default, if x is less than -1 or greater than 1, asin returns an indefinite.
| Input | SEH exception | _matherr exception |
|---|---|---|
| ± INF | INVALID |
_DOMAIN |
| ± QNaN, IND | none | _DOMAIN |
|x| > 1 |
INVALID |
_DOMAIN |
Remarks
Because C++ allows overloading, you can call overloads of asin with float and long double values. In a C program, unless you're using the <tgmath.h> macro to call this function, asin always takes and returns a double.
If you use the asin macro from <tgmath.h>, the type of the argument determines which version of the function is selected. See Type-generic math for details.
By default, this function's global state is scoped to the application. To change this behavior, see Global state in the CRT.
Requirements
| Routine | Required header (C) | Required header (C++) |
|---|---|---|
asin, asinf, asinl |
<math.h> |
<cmath> or <math.h> |
asin macro |
<tgmath.h> |
Example
For more information, see acos, acosf, acosl.
See also
Math and floating-point support
acos, acosf, acosl
atan, atanf, atanl, atan2, atan2f, atan2l
cos, cosf, cosl
_matherr
sin, sinf, sinl
tan, tanf, tanl