The Math.atanh() static method returns the inverse hyperbolic tangent of a number. That is,
βxβ(β1,1),πΌπππ.πππππ(π‘)=artanh(x)=the unique y such that tanh(y)=x=12ln(1+x1βx)\begin{aligned}\forall x \in ({-1}, 1),\;\mathtt{\operatorname{Math.atanh}(x)} &= \operatorname{artanh}(x) = \text{the unique } y \text{ such that } \tanh(y) = x \&= \frac{1}{2}\,\ln\left(\frac{1+x}{1-x}\right)\end{aligned}
Syntax
Math.atanh(x)
Parameters
x- : A number between -1 and 1, inclusive.
Return value
The inverse hyperbolic tangent of x. If x is 1, returns Infinity. If x is -1, returns -Infinity. If x is less than -1 or greater than 1, returns NaN.
Description
Because atanh() is a static method of Math, you always use it as Math.atanh(), rather than as a method of a Math object you created (Math is not a constructor).
Examples
Using Math.atanh()
Math.atanh(-2); // NaN
Math.atanh(-1); // -Infinity
Math.atanh(-0); // -0
Math.atanh(0); // 0
Math.atanh(0.5); // 0.5493061443340548
Math.atanh(1); // Infinity
Math.atanh(2); // NaN