atanh function
Applies to: 
Databricks SQL Databricks Runtime
Returns inverse hyperbolic tangent of expr.
Syntax
atanh(expr)
Arguments
expr: An expression that evaluates to a numeric.
Returns
A DOUBLE.
If the argument is out of bounds, the result is NaN.
Examples
> SELECT atanh(0);
1.0
> SELECT atanh(2);
NaN