acosh

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

Calculates the inverse hyperbolic cosine of x.

Mathematically, acosh(x) = log(x + sqrt( x*x - 1))

1..∞, 0..∞

x, acosh(x)	NaN, NaN	<1, NaN	1, 0	+∞,+∞

fndouble acosh(double x) @safe pure nothrow @nogc

ditto

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

ditto