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Function `std.math.acosh`

Calculates the inverse hyperbolic cosine of x.


						
				real acosh
				(
				

				  real x
				

				) pure nothrow @nogc @safe;
				

				

				double acosh
				(
				

				  double x
				

				) pure nothrow @nogc @safe;
				

				

				float acosh
				(
				

				  float x
				

				) pure nothrow @nogc @safe;

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

Domain X	Range Y
1..∞	0..∞

Special Values
x	acosh(x)
NAN	NAN
<1	NAN
1	0
+∞	+∞

Example

assert(isNaN(acosh(0.9)));
assert(isNaN(acosh(real.nan)));
assert(isIdentical(acosh(1.0), 0.0));
writeln(acosh(real.infinity)); // real.infinity
assert(isNaN(acosh(0.5)));

Authors

Walter Bright, Don Clugston, Conversion of CEPHES math library to D by Iain Buclaw and David Nadlinger

License

Boost License 1.0.