cacos

Complex circular arc cosine.

SYNOPSIS:

void cacos();
cmplx z, w;

cacos(&z, &w);

DESCRIPTION:

w = arccos z = PI/2 - arcsin z.

ACCURACY:

                      Relative error:
arithmetic   domain     # trials      peak         rms
    DEC       -10,+10      5200      1.6e-15      2.8e-16
    IEEE      -10,+10     30000      1.8e-14      2.2e-15