Calculation of Derivative.

Keyword Derivative,Hyperbolic tangent curve.

Reference [1]：オーム社編：『機械工学公式集』,オーム社,pp.20,1960.

Remarks ・LaTeX： \frac{d}{dx}\textup{tanh}\, x=\textup{sech}^{2}\, x\; , \textup{sech}\, x=\frac{1}{\textup{cosh}\, x} ・Making above Equation Image is powered by CODECOGS

History ・2010/02/25：Upload.