The acos() method returns the arccosine of a number as a value value between 0 and PI radians.

The acos() method returns the arccosine of a number as a value value between 0 and PI radians.

If the parameter x is outside the range -1 to 1, the method will return NaN.

-1 will return the value of PI.

Math.acos(x)

Parameter | Require | Description |
---|---|---|

x | Required. | A number |

A Number, from 0 to PI, or NaN if the value is outside the range of -1 to 1

Return the arccosine of a number:

//display the arccosine of 0.5 console.log(Math.acos(0.5));