Hey, I'm trying to find two linear functions, f(r) and h(r) for the following system: dp/dt = A*f(r) dr/dt = -B*h(r) where A and B are constants greater than zero. I'm trying to find linear functions that will tend to equillibrium, and also where limit df(r)/dt = 0 r->0 I have been trying various linear functions and have been unable to come up with a solution. Is there a solution? and if so, what would be one? It's probalby something simple that I'm overlooking. Any help would be appreciated. Thanks.