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

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




A number.

Return value

The hyperbolic arcsine of the given number.


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).


Using Math.asinh()

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


As a quick and dirty hack the expression arsinh(x)=ln(x+x2+1)\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.


Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Math.asinh' in that specification.
Standard Initial definition.
ECMAScript Latest Draft (ECMA-262)
The definition of 'Math.asinh' in that specification.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support38 Yes25 No258
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes Yes Yes25 Yes8 ?

See also

Document Tags and Contributors

 Last updated by: wbamberg,