I actually plotted the phase portrait like this:

with(DEtools);

ode1:= diff(x(t),t) = -4*x(t) + y(t) + 2;

ode2:= diff(y(t),t) = 2*x(t) - 2*y(t) +3;

phaseportrait([ode1,ode2], [x(t), y(t)], t=0..5, [[x(0)=1, y(0)=-1], [x(0)=-1, y(0)=1]], arrows=large, x=-1..1, y=-1..1, linecolor = blue);

Is there anyway i can add my equilibrium lines to this graph  using what i have done or is it better to do it the way you have suggested above?

natalie

I actually plotted the phase portrait like this:

with(DEtools);

ode1:= diff(x(t),t) = -4*x(t) + y(t) + 2;

ode2:= diff(y(t),t) = 2*x(t) - 2*y(t) +3;

phaseportrait([ode1,ode2], [x(t), y(t)], t=0..5, [[x(0)=1, y(0)=-1], [x(0)=-1, y(0)=1]], arrows=large, x=-1..1, y=-1..1, linecolor = blue);

Is there anyway i can add my equilibrium lines to this graph  using what i have done or is it better to do it the way you have suggested above?

natalie