The
asin ();
and the
asinf ();
functions compute the principal value of the arc sine of
Fa x .
A domain error occurs for arguments not in the range
Bq -1 , +1 .
For a discussion of error due to roundoff, see
math(3).
RETURN VALUES
The
asin ();
and the
asinf ();
functions return the arc sine in the range
-words
Bq -/2 , +/2
radians.
If:
| x | > 1
asin (x);
raises an invalid exception and returns an .