phpjs/functions/math/sin.js

php.js offers community built php functions in javascript

function sin(arg) {
  // From: http://phpjs.org/functions
  // +   original by: Onno Marsman
  // *     example 1: sin(8723321.4);
  // *     returns 1: -0.9834330348825929
  return Math.sin(arg);
}