Math.asinh()

The Math.asinh() function returns the hyperbolic arcsine of a number, that is

Math.asinh ( x ) = arsinh ( x ) = the unique y such that sinh ( y ) = x \mathtt{\operatorname{Math.asinh}(x)} = \operatorname{arsinh}(x) = \text{ the unique } ; y ; \text{such that} ; \sinh(y) = x

Syntax

Math.asinh(x)

Parameters

x

A number.

Return value

The hyperbolic arcsine of the given number.

Description

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

Examples

Using Math.asinh()

Math.asinh(1);  // 0.881373587019543
Math.asinh(0);  // 0

Polyfill

Math.asinh can be emulated with the following function:

if (!Math.asinh) Math.asinh = function(x) {
    var absX = Math.abs(x), w
    if (absX < 3.725290298461914e-9) // |x| < 2^-28
        return x
    if (absX > 268435456) // |x| > 2^28
        w = Math.log(absX) + Math.LN2
    else if (absX > 2) // 2^28 >= |x| > 2
        w = Math.log(2 * absX + 1 / (Math.sqrt(x * x + 1) + absX))
    else
        var t = x * x, w = Math.log1p(absX + t / (1 + Math.sqrt(1 + t)))

    return x > 0 ? w : -w
}

Math.log1p may also have to be polyfilled; see Math.log1p for details.

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
asinh
38
12
25
No
25
8
38
38
25
25
8
3.0

See also

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/asinh