Having some trouble with plot and solve

*To*: mathgroup at smc.vnet.net*Subject*: [mg115437] Having some trouble with plot and solve*From*: r_berg <rberg1270 at gmail.com>*Date*: Tue, 11 Jan 2011 00:34:08 -0500 (EST)

Hi i am new to mathematica, i have tried to combine this simple problem of showing a Reaction speed but i cannot plot the tangent line on a plot, and i don't seem to be able to have my regression in the same notebook data = {{0, .005}, {100, .00465}, {200, .00432}, {400, .00374}, {600, \ .00323}, {900, .00260}, {1200, .00209}, {1500, .00168}}; N2O5 = Exp[Fit[data /. {x_, y_} -> {x, Log[y]}, {1, x}, x]] // Simplify (*not in same notebook as the rest*) f[x_] := 0.00499929 E^(-0.000726892 x) (*this works*) g=B4[x_] := -3.63394*10^-6 E^(-0.000726892 x) (*this works*) Plot[0.00499929 E^(-0.000726892 b), {b, 0, 4000}, PlotRange -> {0, .006}](*this works*) Show[Plot[0.00499929 E^(-0.000726892 x), {x, -1000, 4000}], ListPlot[data, PlotRange -> {0, .006}, PlotStyle -> {Red}]] (*this works*) Manipulate[ Solve[g=B4[x0]*{x - x0} + f[x0] == y], {x0, 0, 1500, 1, Appearance -> "Labeled"}] (*this works*) But i cannot combine it together, not even this small thing Manipulate[ Plot[y /. Solve[g\.b4[x0]*{x - x0} + f[x0] == y], {x0, 0, 1500, 1, Appearance -> "Labeled"}], {x, 0, 4000}, PlotRange -> {0, .006}] Please help me, thanks