ARTANH

Syntax ARTANH (x)
Location Hyper

The function ARTANH returns the value which must be passed to TANH to give the specified result, so:

TANH ( ARTANH ( x )) = ARTANH ( TANH ( x )) = x

ARTANH(x) could be replaced by: LN((1+x) / (1-x)) / 2

CROSS-REFERENCE

See ATAN, ARCOTH, and ARSINH.