Math.asinh()

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

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

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

As a quick and dirty hack the expression $\operatorname {arsinh} (x) = \ln \left(x + \sqrt{x^{2} + 1} \right)$ may be used directly for a coarse emulation by the following function:

Math.asinh = Math.asinh || function(x) {
  if (x === -Infinity) {
    return x;
  } else {
    return Math.log(x + Math.sqrt(x * x + 1));
  }
};

Been formally correct it suffers from a number of issues related to floating point computations. Accurate result requires special handling of positive/negative, small/large arguments as it done e.g. in glibc or GNU Scientific Library.

Specifications

Browser compatibility

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

See also

• Math.acosh()
• Math.atanh()
• Math.cosh()
• Math.sinh()
• Math.tanh()