Returns the arcsine (in radians) of a number.

Method of Math
Static

Syntax

Parameters

Description

The asin method returns a numeric value between -pi/2 and pi/2 radians. If the value of number is outside this range, it returns NaN.
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.

Examples

The following function returns the arcsine of the variable x:

If you pass getAsin the value 1, it returns 1.570796326794897 (pi/2); if you pass it the value 2, it returns NaN because 2 is out of range.

See also

Math.acos, Math.atan, Math.atan2, Math.cos, Math.sin, Math.tan