JavaScript asin() Method

Definition and Usage

The asin() method returns the arcsine of a number as a numeric value between
-PI/2 and PI/2 radians.

Syntax

Math.asin(x)

Parameter	Description
x	Required. Must be a numeric value in the range -1 to 1

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Tips and Notes

Note: If the parameter x is outside the range -1 to 1, the browser will return NaN.
Note: 1 will return the value of PI/2.

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Example

In this example we will get the arcsine of different numbers:

<script type="text/javascript"> document.write(Math.asin(0.64) + "<br />"); document.write(Math.asin(0) + "<br />"); document.write(Math.asin(-1) + "<br />"); document.write(Math.asin(1) + "<br />"); document.write(Math.asin(2)); </script>

The output of the code above will be:

0.6944982656265559 0 -1.5707963267948965 1.5707963267948965 NaN