Re: Simple equation won't plot

*To*: mathgroup at smc.vnet.net*Subject*: [mg82952] Re: [mg82917] Simple equation won't plot*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Sun, 4 Nov 2007 06:14:15 -0500 (EST)*Reply-to*: hanlonr at cox.net

When I paste your statement into a notebook, the word Plot isn't recognized as a reserved word. Doubleclicking it and retyping Plot fixed this and everything worked as expected. Perhaps there is a hidden character in the expression. The t_ is a pattern with the name t and specifies that the argument can be anything not just t. Look up Blank. Bob Hanlon ---- "Bert Aerts (rm x)" <bert.aertsx at advalvasx.be> wrote: > When I type following commands in Mathematica 6.0.1: > m = 70; a = 0.08; x0 = 5000; g = 9.81; > x[t_] = x0 - m*Log[Cosh[t*Sqrt[g*a]/Sqrt[m]]]/a; > P1ot[x[t], {t, 0, 60}] > I don't get a plot, but instead: > P1ot[5000 - 875. Log[Cosh[0.105884 t]], {t, 0, 60}] > How can I get a real plot? I tried [N[x[t]] and Evaluate[x[t]] but nothing > worked... > Why is t_ used in the second equation? > The source of these equations is Ferdinand F. Cap's book "Mathematical > methods in physics and engineering with Mathematica" > >