7.12.4.2 The asin functions
Synopsis
#include <math.h>
double asin(double x);
float asinf(float x);
long double asinl(long double x);
Description
The asin functions compute the principal value of the arc sine of x. A domain error occurs for arguments not in the interval [-1, +1].
Returns
The asin functions return arcsin x in the interval [-pi /2, +pi /2] radians.