src/complex/casin.c

   1 #include "complex_impl.h"
   2
   3 // FIXME
   4
   5 /* asin(z) = -i log(i z + sqrt(1 - z*z)) */
   6
   7 double complex casin(double complex z)
   8 {
   9         double complex w;
  10         double x, y;
  11
  12         x = creal(z);
  13         y = cimag(z);
  14         w = CMPLX(1.0 - (x - y)*(x + y), -2.0*x*y);
  15         double complex r = clog(CMPLX(-y, x) + csqrt(w));
  16         return CMPLX(cimag(r), -creal(r));
  17 }