asin(3M) Mathematical Library Functions asin(3M)NAME
asin, asinf, asinl - arc sine function
SYNOPSIS
c99 [ flag... ] file... -lm [ library... ]
#include <math.h>
double asin(double x);
float asinf(float x);
long double asinl(long double x);
DESCRIPTION
These functions compute the principal value of the arc sine of their
argument x. The value of x should be in the range [−1,1].
RETURN VALUES
Upon successful completion, these functions return the arc sine of x in
the range [−pi/2, pi/2] radians.
For finite values of x not in the range [−1,1], a domain error occurs
and a NaN is returned.
If x is NaN, NaN is returned.
If x is ±0, x is returned.
If x is ±Inf, a domain error occurs and a NaN is returned.
For exceptional cases, matherr(3M) tabulates the values to be returned
by asin() as specified by SVID3 and XPG3.
ERRORS
These functions will fail if:
Domain Error The x argument is finite and not in the range [−1,1],
or is ±Inf.
If the integer expression (math_errhandling &
MATH_ERREXCEPT) is non-zero, the invalid floating-point
exception is raised.
The asin() function sets errno to EDOM if x is not ±Inf
or NaN and is not in the range [−1,1].
USAGE
An application wanting to check for exceptions should call feclearex‐
cept(FE_ALL_EXCEPT) before calling these functions. On return, if
fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is
non-zero, an exception has been raised. An application should either
examine the return value or check the floating point exception flags to
detect exceptions.
An application can also set errno to 0 before calling asin(). On
return, if errno is non-zero, an error has occurred. The asinf() and
asinl() functions do not set errno.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Committed │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │MT-Safe │
├─────────────────────────────┼─────────────────────────────┤
│Standard │See standards(5). │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOisnan(3M), feclearexcept(3M), fetestexcept(3M), math.h(3HEAD), math‐
err(3M), sin(3M), attributes(5), standards(5)SunOS 5.11 12 Jul 2006 asin(3M)