# Math.asin()

The Math.asin() function returns the inverse sine (in radians) of a number. That is,

## Syntax

Math.asin(x)


### Parameters

x

A number between -1 and 1, inclusive, representing the angle's sine value.

### Return value

The inverse sine (angle in radians between $-\frac\left\{\pi\right\}\left\{2\right\}$ and $\frac\left\{\pi\right\}\left\{2\right\}$, inclusive) of x. If x is less than -1 or greater than 1, returns NaN.

## Description

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

## Examples

### Using Math.asin()

Math.asin(-2); // NaN
Math.asin(-1); // -1.5707963267948966 (-π/2)
Math.asin(-0); // -0
Math.asin(0); // 0
Math.asin(0.5); // 0.5235987755982989 (π/6)
Math.asin(1); // 1.5707963267948966 (π/2)
Math.asin(2); // NaN


## Specifications

Specification
ECMAScript Language Specification
# sec-math.asin

## Browser compatibility

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