Why are the functions different?

*To*: mathgroup at smc.vnet.net*Subject*: [mg55609] Why are the functions different?*From*: Helge Stenstroem <helge.stenstrom.NOSPAM at NOSPAMericsson.com>*Date*: Thu, 31 Mar 2005 01:24:00 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

How are these two functions (f0 and f1) different? f0 can be plotted, but f1 cannot. f1[x_] := Normal[Series[Tanh[x], {x, 0, 5}]] f0[x_] := x - x^3/3 + (2*x^5)/15 When evaluated like this: f0[x] f1[x] they look the same. The following gives error messages if f0 is replaced by f1. Plot[{Tanh[z], f0[z]}, {z, -1, 1}] (Mathematica 4.1 on Windows 2000) -- Helge Stenström