View source code
Display the source code in std/math/trigonometry.d from which this page was generated on github.
Report a bug
If you spot a problem with this page, click here to create a Bugzilla issue.
Improve this page
Quickly fork, edit online, and submit a pull request for this page. Requires a signed-in GitHub account. This works well for small changes. If you'd like to make larger changes you may want to consider using local clone.

Function std.math.trigonometry.cos

Returns cosine of x. x is in radians.

real cos (
  real x
) pure nothrow @nogc @safe;

double cos (
  double x
) pure nothrow @nogc @safe;

float cos (
  float x
) pure nothrow @nogc @safe;

Special Values
x cos(x) invalid?
NAN NAN yes
±∞ NAN yes

Bugs

Results are undefined if |x| >= 264.

Example

import std.math.operations : isClose;

writeln(cos(0.0)); // 1.0
assert(cos(1.0).isClose(0.5403023059));
assert(cos(3.0).isClose(-0.9899924966));

Authors

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

License

Boost License 1.0.