ASIN(N) Linux Programmer's Manual ASIN(N) NAME asin - arc sine function SYNOPSIS #include <math.h> double asin(double x); DESCRIPTION The asin() function calculates the arc sine of x; that is the value whose sine is x. If x falls outside the range -1 to 1, asin() fails and errno is set. RETURN VALUE The asin() function returns the arc sine in radians and the value is mathematically defined to be between -PI/2 and PI/2 (inclusive). ERRORS EDOM x is out of range. CONFORMING TO SVID 3, POSIX, BSD 4.3, ISO 9899 SEE ALSO acos(s), atan(n), atan2(2), cos(s), sin(n), tan(n) 1993-06-08 ASIN(N)