https://docs.oracle.com/cd/E86824_01/html/E54769/cacosf-3m.html
cacosf - man pages section 3: Extended Library Functions, Volume 2
cacos , cacosf , cacosl - complex arc cosine functions These functions compute the complex arc cosine of z , with branch cuts outside the interval [ -1, +1 ]...
man pagesextended librarycacosfsectionfunctions
https://docs.oracle.com/cd/E88353_01/html/E37846/cacosf-3m.html
cacosf - man pages section 3: Extended Library Functions, Volume 2
cacos , cacosf , cacosl - complex arc cosine functions These functions compute the complex arc cosine of z , with branch cuts outside the interval [ -1, +1 ]...
man pagesextended librarycacosfsectionfunctions