JavaScript Math asin()

The Math.asin() function in JavaScript is used to calculate the arcsine of a number. It returns the value in radians between -π/2 and π/2.

Syntax

The syntax for using the asin() function is as follows:

Math.asin(x)

Where x is the number whose arcsine needs to be calculated.

Parameters

The asin() function takes only one parameter:

• x (required): The number for which the arcsine needs to be calculated. It should be between -1 and 1.

Return Value

The asin() function returns a number representing the arcsine of the given number in radians. The result is NaN (Not a Number) if the argument is outside the range of -1 to 1.

Examples

Here are a few examples to demonstrate the usage of the Math.asin() function:

Math.asin(0);      // 0
Math.asin(1);      // 1.5707963267948966 (equivalent to π/2)
Math.asin(-1);     // -1.5707963267948966 (equivalent to -π/2)
Math.asin(0.5);    // 0.5235987755982989 (equivalent to π/6)
Math.asin(-0.5);   // -0.5235987755982989 (equivalent to -π/6)
Math.asin(2);      // NaN (outside the range of -1 to 1)
Math.asin(-2);     // NaN (outside the range of -1 to 1)

Notes

• The Math.asin() function uses the standard trigonometric identity arcsin(x) = sin^(-1)(x).
• The input value (x) must be between -1 and 1. If the value is outside this range, the function returns NaN.
• The result of Math.asin() is in radians. If you need the result in degrees, you can convert it using the formula: degrees = radians * (180 / π).

For more information, refer to the MDN web docs.