1. Solve by separation of variables and plot the solution to the ODE: dx/dt =x.
x.=4x-2; t≥1, x(1)= 3/4
2. Solve the equation x. = -x ln(x),t≥0, x(0) = xo
What is the asymtotic value of x at t→∞. EXPLAIN your answer.
3. For the given graph, re-sketch a graph for x01 and indicate the system progress (using arrows and EXPLAIN) from x01 as t→∞. Identify any critical points as stable, unstable, or semi-stable (EXPLAIN). Repeat for x02 , x03, and x04.
4. Draw and label the phase diagram (x. vs. x). Indicate the system progress (using arrows and EXPLAIN). Identify any critical points as stable, unstable, or semi-stable (EXPLAIN): x. = a1x-a2, a1>0 , a2>0.
5. Draw and label the phase diagram(x. vs. x) for x. = 3x2 - 9x. Indicate the system progress (using arrows and EXPLAIN). Identify any critical points as stable, unstable, or semi-stable (EXPLAIN).
6. A harvesting model is represented by: x. = a1x-a2x2-h; a1>0 , a2>0, h>0.
a. Draw the phase diagram ( (ivs.x) and label the values of the intercepts and the point of maximum x.
b. Identify any critical points as stable, unstable, or semi-stable (EXPLAIN).
c. What values of h doom the crop to complete depletion (EXPLAIN)?
d. What is the maximum value of h that produces a critical crop level (EXPLAIN).
e. Plot x. vs. x for maximum h and determine if the critical point is stable, unstable, or semi-stable (EXPLAIN).
f. How does the maximum value of h change if al, the reproduction rate parameter, increases (EXPLAIN)?
g. How does the maximum value of h change if al, the reproduction rate parameter, decreases (EXPLAIN)?
7. x. = a1x-a2 If x has units of ounces and x. has units of ounces per second, what are the units of a1 and a2 (EXPLAIN)?