Tanh[ArcTanh[z]] == z
Cell[BoxData[RowBox[List[RowBox[List["Tanh", "[", RowBox[List["ArcTanh", "[", "z", "]"]], "]"]], "\[Equal]", "z"]]]]
<math xmlns='http://www.w3.org/1998/Math/MathML' mathematica:form='TraditionalForm' xmlns:mathematica='http://www.wolfram.com/XML/'> <semantics> <mrow> <mrow> <mi> tanh </mi> <mo> ⁡ </mo> <mo> ( </mo> <mrow> <msup> <mi> tanh </mi> <mrow> <mo> - </mo> <mn> 1 </mn> </mrow> </msup> <mo> ( </mo> <mi> z </mi> <mo> ) </mo> </mrow> <mo> ) </mo> </mrow> <mo> ⩵ </mo> <mi> z </mi> </mrow> <annotation-xml encoding='MathML-Content'> <apply> <eq /> <apply> <tanh /> <apply> <arctanh /> <ci> z </ci> </apply> </apply> <ci> z </ci> </apply> </annotation-xml> </semantics> </math>
Cell[BoxData[RowBox[List[RowBox[List["HoldPattern", "[", RowBox[List["Tanh", "[", RowBox[List["ArcTanh", "[", "z_", "]"]], "]"]], "]"]], "\[RuleDelayed]", "z"]]]]
2001-10-29
){kind=small}
