asinpi3
Half-cycle arc sine functions
Usage
#include <math.h>
double
asinpi(double x);
float
asinpif(float x);
long double
asinpil(long double x);
Library
Math Library (libm, -lm)
Overview
The asinpi(), asinpif(), and asinpil() functions compute the principal value of the arc sine of x, divided by , thus measuring the angle in half-cycles.
Return values
The asinpi(), asinpif(), and asinpil() functions return values in the range [-1, +1]. If |x| > 1, asinpi(x) raises an invalid exception and returns an .