Plot[1-Tanh[x]^2,{x,-10,10}, PlotRange->All]

Export["C:\\Users\\kfrin\\Desktop\\TanhData.dat",Table[{x,1-Tanh[x]^2},{x,-10,10,0.001}]]

DATA = Table[{x,1-Tanh[x]^2},{x,-10,10,0.001}];

Length[DATA]

DATA[[10000]]

DATA[[10001]]

DATA[[10002]]

D[Tanh[x],x]

D[1-Tanh[x]^2,x]

Plot[{1-Tanh[x]^2,-2 ((Sech[x])^2) Tanh[x]},{x,-10,10}, PlotRange->All]

FDATA = Import["C:\\Users\\kfrin\\Desktop\\funcdata.dat"];

ListPlot[FDATA, PlotStyle->Red, PlotRange->All]

DiffData  =Table[{DATA[[k,1]],Abs[FDATA[[k,1]]-DATA[[k,1]]]},{k,1,20001}];

ListPlot[DiffData]