#include "libm.h"

/* acosh(z) = i acos(z) */

double complex cacosh(double complex z)
{
        _Bool zineg = cimag(z) < 0;

	z = cacos(z);
	if (zineg) return CMPLX(cimag(z), -creal(z));
	else       return CMPLX(-cimag(z), creal(z));
}