Math.cos()
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
TheMath.cos() static method returns the cosine of a number in radians.
Try it
function getCircleX(radians, radius) { return Math.cos(radians) * radius;}console.log(getCircleX(1, 10));// Expected output: 5.403023058681398console.log(getCircleX(2, 10));// Expected output: -4.161468365471424console.log(getCircleX(Math.PI, 10));// Expected output: -10Syntax
js
Math.cos(x)Parameters
xA number representing an angle in radians.
Return value
The cosine ofx, between -1 and 1, inclusive. Ifx isInfinity,-Infinity, orNaN, returnsNaN.
Description
Becausecos() is a static method ofMath, you always use it asMath.cos(), rather than as a method of aMath object you created (Math is not a constructor).
Examples
Using Math.cos()
js
Math.cos(-Infinity); // NaNMath.cos(-0); // 1Math.cos(0); // 1Math.cos(1); // 0.5403023058681398Math.cos(Math.PI); // -1Math.cos(2 * Math.PI); // 1Math.cos(Infinity); // NaNSpecifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-math.cos |