For each of the systems in 4 through 13: a. Find all the critical points (equilibrium solutions). G b. Use an appropriate graphing device to draw a direction field and phase portrait for the system. c. From the plot(s) in part b, determine whether each critical point is asymptotically stable, stable, or unstable, and classify it as to type. d. Describe the basin of attraction for each asymptotically stable critical point.dx/dt = (2 + y)( x + y), dy/dt = y(1 x)

L20 - 7 Logarithmic Diﬀerentiation 1. Take natural logarithms of both sides of an equation y = f(x)andueheawsfoahmsoi . 2. Diﬀerentiate implicitly with respect to x. 3. Solve fordy . dx We...