@Kitonum , that worked. Thanks so much.

Thanks for your help. I realized I was being dumb, and had unassigned the ODE2 before trying to plot it. It's working now.

This is copied and pasted from the maple worksheet...

(c) Use DEplot to sketch a direction field for my_deq and the solution curve for the initial condition T(0) = 88 C. Assign your plot to my_plot.

restart; ODE2:=(Diff(T(t),t)=1/59*(18-T(t))):

with(DEtools); DEplot(ODE2, T(t), t = -4 .. 4, {[T(0) = 88]}, T = 0 .. 100);

Error, (in DEtools/DEplot/CheckInitial) the 'number' option must be specified before initial conditions

I'm not sure why this is happening, especially when I followed the exact thing you typed.

Thanks!