As part of a recent assignment I have been asked to draw a phase line for the function . I can find the main equilibrium point easily ( ) but the problem I have is that are also solutions. So in a way I have a phase line that continues infinitely. Is there any formal way of setting this out. The main idea that comes to mind is including an algebraic multiplier of both 180 and -180 on the phase line the stating when is the multiplier.