C/math.h/atanh
atanh: returns the arc hyperbolic tangent of arg
//Declaration: float atanhf(float arg);
double atanh(double arg);
long double atanhl(long double arg);
//Parameter: This argument must be in the range -1 to 1.
#include <math.h>
#include <stdio.h>
int main(void)
{
printf("%f.\n", atanh(12));
return 0;
}
/*
-1.#IND00.
*/