 # JavaScript Math asin()

The `asin()` method calculates the arcsine (inverse of sine) of the specified angle and returns it.

### Example

``````let value = Math.asin(1);
console.log(value);

// Output: 1.5707963267948966``````

## asin() Syntax

The syntax of the `Math.asin()` method is:

``Math.asin(angle)``

Here, `asin()` is a static method. Hence, we are accessing the method using the class name, `Math`.

## asin() Parameter

The `asin()` method takes a single parameter:

• `angle` - in radians whose arcsine is to be calculated

Note: The value of `angle` should be between -1 and 1.

## asin() Return Value

The `asin()` method returns:

• arcsine value of the `angle`
• NaN (Not a Number) if the argument is either non-numeric or greater than 1 or less than -1

## Example 1: Math.asin() with argument between -1 and 1

``````// arcsine of negative number
let number1 = Math.asin(-1);
console.log(number1);

// arcsine of positive number
let number2 = Math.asin(0.5);
console.log(number2);

// Output:
// -1.5707963267948966
// 0.5235987755982989``````

In the above example, the `Math.asin()` method computes the arcsine of

• `-1` (negative number) - results in -1.5707963267948966
• `0.5` (positive number) - results in 0.5235987755982989

## Example 2 : Math.asin() for other Argument not in the range -1 and 1

``````// argument less than -1
let number1 = Math.asin(-100);
console.log(number1);
// Output: NaN

// argument greater than 1
let number2= Math.asin(32);
console.log(number2);
// Output: NaN    ``````

Here, we get `NaN` as output because both the arguments, -100 and 32, are not in the range -1 and 1.

## Example 3: Math.asin() with Non-Numeric Argument

``````let string = "Harry";

// asin() with a string argument
let value = Math.asin(string);
console.log(value);

// Output:
// NaN``````

In the above example, we have tried to calculate the arcsine of the string `"Harry"`. That's why we get NaN as the output.