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JavaScript asin() Method

Math Object Reference JavaScript Math Object

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

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.

Example

Example

Return 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

Try it yourself »

Math Object Reference JavaScript Math Object

From http://www.w3schools.com (Copyright Refsnes Data)