The acos()
method calculates the arc-cosine (inverse of cosine) of the specified angle and returns it.
Example
let value = Math.acos(0.45);
console.log(value);
// Output: 1.1040309877476002
acos() Syntax
The syntax of the Math.acos()
method is:
Math.acos(angle)
Here, acos()
is a static method. Hence, we are accessing the method using the class name, Math
.
acos() Parameter
The acos()
method takes a single parameter:
angle
(radians) - in range -1 to 1 whose arc-cosine is to be calculated
acos() Return Value
The acos()
method returns:
- arc-cosine value of the
angle
- NaN (Not a Number) for argument greater than 1 or less than -1 or non-numeric
Example 1: Math.acos() with Arguments Between -1 and 1
// arc-cosine of negative number
let number1 = Math.acos(-1);
console.log(number1);
// arc-cosine of positive number
let number2 = Math.acos(0.5);
console.log(number2);
// Output:
// 3.141592653589793
// 1.0471975511965979
In the above example, the Math.acos()
method computes the arc-cosine of
-1
(negative number) - results in 3.1415926535897930.5
(positive number) - results in 1.0471975511965979
Example 2 : Math.acos() with Arguments Not Between -1 and 1
// argument less than -1
let number1 = Math.acos(-3);
console.log(number1);
// Output: NaN
// argument greater than 1
let number2= Math.acos(32);
console.log(number2);
// Output: NaN
Here, we have used the Math.acos()
method with values -3 (less than -1) and 32 (greater than 1). For both values, we get NaN as output.
Example 3: Math.acos() with Non-Numeric Argument
let string = "Harry";
// acos() with a string argument
let value = Math.acos(string);
console.log(value);
// Output:
// NaN
In the above example, we have used Math.acos()
with a string value, "Harry"
. Hence, we get NaN as the output.
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