asin - arc sine function
cc [ flag ... ] file ... -lm [ library ... ]
double asin(double x);
The asin() function computes the principal value of the arc
sine of x. The value of x should be in the range [-1,1].
Upon successful completion, asin() returns the arc sine of
x, in the range [-pi/2,pi/2] radians. If the value of x is
not in the range [-1,1] and is not _Inf or NaN, either 0.0
or NaN is returned and errno is set to EDOM.
If x is NaN, NaN is returned.
If x is _Inf, either 0.0 is returned and errno is set to
EDOM or NaN is returned and errno may be set to EDOM.
For exceptional cases, matherr(3M) tabulates the values to
be returned as dictated by Standards other than XPG4.
The asin() function will fail if:
EDOM The value x is not _Inf or NaN and is not in the range
The asin() function may fail if:
EDOM The value of x is _Inf.
An application wishing to check for error situations should
set errno to 0, then call asin(). If errno is non-zero on
return, or the return value is NaN, an error has occurred.
See attributes(5) for descriptions of the following attri-
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| MT-Level | MT-Safe |
isnan(3M), matherr(3M), sin(3M), attributes(5), standards(5)
Man(1) output converted with