# ATANH scalar function

Returns the hyperbolic arctangent of the argument, where the argument is an angle expressed in radians.

The schema is SYSIBM.

- expression
- An expression that returns a value of any built-in numeric data type except for DECFLOAT. The value is converted to a double-precision floating-point number for processing by the function.

The result of the function is a double-precision floating-point number. The result can be null if the argument can be null or the database is configured with dft_sqlmathwarn set to YES; the result is the null value if the argument is null.