JavaScript Math acos() Method

The Javascript Math.acos( ) method is used to return the arccosine of a number in radians. The Math.acos() method returns a numeric value between 0 and pi radians. The Math acos() is a static method of Math, therefore, it is always used as Math.acos(), rather than as a method of a Math object created.

Math.acos(x)=arccos(x)=unique y, where y belongs to [0;pi] such that cos(y)=x

Syntax:

Math.acos(value)

Parameters: This function accepts a single parameter as mentioned above and described below:

• Value: It is a number in radians whose arccosine you want to find.

Return value: The Math.acos() function returns the arccosine of the given number in radians. 

The below examples illustrate the Math acos( ) method in JavaScript:

Example 1: When 1 is passed as a parameter.

javascript

console.log("When 1 is passed as a parameter: "
    + Math.acos(1));

Output:

When 1 is  passed as a parameter: 0

Example 2: When -1 is passed as a parameter.

javascript

console.log("When -1 is passed as a parameter: "
    + Math.acos(-1));

Output:

When 1 is  passed as a parameter: 3.141592653589793

Example 3: When 0 is passed as a parameter.

javascript

console.log("When 0 is passed as a parameter: "
    + Math.acos(0));

Output:

When 0 is  passed as a parameter: 1.5707963267948966

Example 4: When 0.5 is passed as a parameter.

javascript

console.log("When 0.5 is  passed as a parameter: "
    + Math.acos(0.5));

Output:

When 0.5 is  passed as a parameter: 1.0471975511965979

Example 5: When 2 is passed as a parameter.

javascript

console.log("When 2 is  passed as a parameter: "
    + Math.acos(2));

Output:

When 2 is  passed as a parameter: NaN

We have a complete list of Javascript Math Objects methods, to check those please go through this Javascript Math Object Complete reference article.

Supported Browsers:

• Google Chrome 1 and above
• Internet Explorer 3 and above
• Firefox 1 and above
• Opera 3 and above
• Safari 1 and above