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Function `std.math.trigonometry.acos`

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


						
				real acos(
				
  real x
				

				) pure nothrow @nogc @safe;
				

				

				double acos(
				
  double x
				

				) pure nothrow @nogc @safe;
				

				

				float acos(
				
  float x
				

				) pure nothrow @nogc @safe;

Special Values
x	acos(x)	invalid?
>1.0	NAN	yes
<-1.0	NAN	yes
NAN	NAN	yes

Example

import std.math.operations : isClose;
import std.math.traits : isNaN;
import std.math.constants : PI;

assert(acos(0.0).isClose(1.570796327));
assert(acos(0.5).isClose(PI / 3));
assert(acos(PI).isNaN);

Authors

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

License

Boost License 1.0.