Midterm Exam 1 (Solutions!)
September 25, 2013
Answer each of the following questions, being sure to start each problem on a
separate piece of paper. To obtain full credit for a solution, you must provide
full justication for your solutions. That is, it i
Math 221 Answers to Practice Problems for
Midterm Exam 1
1. (a) 4th order, nonlinear. (b) 3rd order, linear. (c) 2nd order, nonlinear. (d) 6th order,
linear. (e) 1st order, nonlinear.
2. (a) (, 1). (b) ( 3, 3).
3. General solution to the ODE is
y = 0 or y
Midterm Exam 2 (Solutions!)
October 28, 2013
Answer each of the following questions, being sure to start each problem on a
separate piece of paper. To obtain full credit for a solution, you must provide
full justication for your solutions. That is, it is
Math 221 Answers to Practice Problems for
Midterm Exam 2
1. (a) y (t) = c1 cos(t) + c2 sin(t).
(b) y (t) = c1 + c2 ex .
(c) y (t) = c1 et/2 + c2 tet/2 .
(d) y (t) = c1 et cos(t) + c2 et sin(t).
2. (a) y (t) = et .
1
(b) y (t) = cos(2t) 2 sin(2t).
1
(c) y