Determine the critical points and identify them as asymptotically stable or unstable? Drawing phase lines? Here's the question: 
Determine the critical (equilibrium) points, and classify each one as
asymptotically stable or unstable. Draw the phase line, and sketch
several graphs of solutions in the $ty$-plane
$$dy/dt = 1 − e^y,\; −∞ < y_0 < ∞.$$ 
This section of the textbook is all about population growth and is supposed to be in the form $dy/dt=r(1-y/k)y$, so I don't understand how to find the critical pts. in this case. Do I have to actually solve the DE to graph the solutions? Is the phase line just the $y$-axis?

The only equilibrium point of $$dy/dt = 1 −    e^y,\; −∞ < y_0 < ∞.$$ is at  $dy/dt =0.$ 
Thus  equilibrium happens at $$ e^y =1 $$ that is  $y=0$ 
This equilibrium is asymptotically stable because  $y>0 \implies  dy/dx <0$ and  $ y<0 \implies dy/dx>0.$
Therefore the solutions approach the equilibrium solution $y=0$ asymptotically.     
