SYNOPSIS
#include <math.h> double asin(double x); float asinf(float x);
DESCRIPTION
asin
computes the inverse sine (arc sine)
of the argument, x.
Arguments to asin
must be in the range -1 to 1.
asinf is identical to asin, other than taking and returning floats.
You can modify error handling for these routines using matherr.
RETURNS
asin
returns values in radians, in the range
of -
/2
to /2.
If x is not in the range -1 to 1, asin and asinf return NaN (not a number), set the global variable errno to EDOM, and issue a DOMAIN error message.
You can change this error treatment using matherr.