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Re: changing variable in an equation
Posted:
Feb 13, 2011 5:51 AM


Hi,
> Those that have responded have requested further information. I hope this > will help. > ... > What I tried to do was to just plot his solution which is V(t)= Vsubnl + (V0 >  Vsubnl)times e to the gsubL * t divided by c. What I did was make up > different equations such as vt1 = 67+(0(67))*e^19t/c and substitute > values for t. And then make another equation with a different V0 and do the > same thing. Then finally combine them using Plot{{vt1,vt2 and so on}, > {t,0,5}]. > > These results mimic his plots so I am on the right track. It's just that my > way takes an enormous amount of time. I know that there must be a better > way to do this with Mathematica. That's the whole point of my request for > help.
I'm not sure whether I got what you want and don't have the book to check, but I think the following should be a starting point to achieve what you probably want:
sol = VsubnL + (V0  VsubnL)*E^(gsubL*t/c)
parameters = {c > 10, gsubL > 19, VsubnL > 67}
Plot[Evaluate[Table[sol /. parameters, {V0, 0, 100, 20}]], {t, 0, 5}, Frame > True, Axes > False, PlotRange > All, ImageSize > 500]
hth,
albert



