acos

fnreal acos(real x) @safe pure nothrow @nogc

Calculates the arc cosine of x, returning a value ranging from 0 to π.

x acos(x) invalid?
≥1.0 NaN yes
<-1.0 NaN yes
NaN NaN yes
fndouble acos(double x) @safe pure nothrow @nogc

ditto

fnfloat acos(float x) @safe pure nothrow @nogc

ditto