hphp/hack/manual/hsl/Functions/HH.Lib.Math/sin.md
:::info[Note] This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information. :::
Returns the sine of $arg
namespace HH\Lib\Math;
function sin(
num $arg,
): float;
Math\cos().Math\tan().num $argfloat$rotation = 0;
$result = Math\sin($rotation);
echo "Math\sin of $rotation : $result \n";
$rotation = 90;
$result = Math\sin($rotation);
echo "Math\sin of $rotation : $result \n";
$rotation = 180;
$result = Math\sin($rotation);
echo "Math\sin of $rotation : $result \n";