### How do you overlay trajectory graphs on vector fields?

Hi, I'm doing a programming problem where I have to graph a vector field, then overlay trajectory graphs with different initial values on it.

So far this is what I have:

**var('R, S')**

**plot_vector_field([3***R - R^2 - 2*R*S, 2*S - S^2 - R*S], (R,-50, 50), (S, -50, 50))

**R = sol[:,0]**

**S = sol[:,1]**

**list_plot(zip(R,S), plotjoined=True)****

The last line always produces a separate graph. I've tried using the "**+**" operator to "add" it to the vector field graph, but that gives me an error instead. I also don't know how to repeat the process (i.e. overlay additional trajectories) without having to make a new graph for each. Truth be told I'm only a beginning coder and have some trouble synthesizing different coding aspects together.

Any help would be greatly appreciated!