I am trying to get a shaded area in my plot but I could not.
First we solve ODE without randomness:
ode := diff(U(t), t) = -(A+B*U(t))*U(t);
Then we add randomness to ODE and solve:
ode2 := diff(U(t), t) = -(A+r(t)+B*U(t))*U(t);
A with randomness for r in R=( - 0.0001/365, 0.0001/365) is:
Where A is constant = 0.0001/365
We plot both solution. For the plot I...