#include "libm.h" // FIXME /* asin(z) = -i log(i z + sqrt(1 - z*z)) */ double complex casin(double complex z) { double complex w; double x, y; x = creal(z); y = cimag(z); w = CMPLX(1.0 - (x - y)*(x + y), -2.0*x*y); return clog(CMPLX(-y, x) + csqrt(w)); }