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Question: ODE Plotting Question

Question:ODE Plotting Question

FJMoesler 20 Maple
example derivative format
November 21 2006
0
I'm having problems plotting the derivative of a function after I've solved the ODE in an ODE system. Any help appreciated! The MAPLE help for plots,odeplot says: "Multiple curves can be plotted by specifying a nested list format. For example, [[x,y(x)],[x,diff(y(x),x)]] displays the dependent variable and its derivative as a function of x on the same plot." So, here's my problem. I define mtest with my two ODE's and two initial values, and solve it numerically over my specified range. This works great. mtest := [diff(m(t), t) = -43/25*exp(-8527.784461/(pt(t)+273.15)+19.03523317)*(m(t)-exp(-23300/(8.314*pt(t)+2270.96910)+2.646139043)), diff(pt(t), t) = 240, m(0) = 1, pt(0) = 105]; sol1 := dsolve(mtest,type=numeric, range=0..1); but using the plots[odeplot], I only get the m(t) plot, not the diff(m(t),t) plot. plots[odeplot](sol1, [[t, m(t),color=green],[t,diff(m(t),t),color=blue]], 0 .. 1); However, if I use the interactive solver, I can get the plot to occur, but the interactive solver puts in the solution for the diff, not the term "diff(m(t),t)", limiting my usage to that particular solution. Any idea what I'm doing wrong? I believe it has to be relatively simple.
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