Math.cos()

Baseline Widely available

This feature is well established and works across many devices and browser versions. Its been available across browsers since July 2015.

Learn more
See full compatibility

The Math.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: 5.403023058681398

console.log(getCircleX(2, 10));
// Expected output: -4.161468365471424

console.log(getCircleX(Math.PI, 10));
// Expected output: -10

Syntax

Math.cos(x)

Parameters

x: A number representing an angle in radians.

Return value

The cosine of x, between -1 and 1, inclusive. If x is Infinity, -Infinity, or NaN, returns NaN.

Description

Because cos() is a static method of Math, you always use it as Math.cos(), rather than as a method of a Math object you created (Math is not a constructor).

Examples

Using Math.cos()

Math.cos(-Infinity); // NaN
Math.cos(-0); // 1
Math.cos(0); // 1
Math.cos(1); // 0.5403023058681398
Math.cos(Math.PI); // -1
Math.cos(2 * Math.PI); // 1
Math.cos(Infinity); // NaN