Practice for Exam 1
Math 3400 - Intro to Dierential Equations
Spring 2012 - Dr. Radu Cascaval
Problem 1. Solve the dierential equations
(a) y = 2xy 2
(b) y + 2y = xe2x
(c)
dx
dt
= 1 x2
Problem 2. Solve the initial value problem
dy
= x(1 y 2 ),
dx
y(0) = 2
Practice for Final Exam
Math 3400 - Intro to Dierential Equations
Spring 2012 - Dr. Radu Cascaval
The rst 20 (multiple-choice) problems are 5 points each, the remaining 5 (essay) problems are 10
points each (Show all work to get full credit on the essay p
Practice for Exam 2
Math 3400 - Intro to Dierential Equations
Spring 2012 - Dr. Radu Cascaval
Problem 1. The motion of a forced spring-mass system is described by the equation mx + kx = F cos t, where
m = 4 g, k = 16 g/s2 and the forcing has amplitude F =
Solutions to Practice for Final Exam
Math 3400 - Intro to Dierential Equations
Spring 2012 - Dr. Radu Cascaval
The rst 20 (multiple-choice) problems are 5 points each, the remaining 5 (essay) problems are 10
points each (Show all work to get full credit o
Solutions to FINAL EXAM
MATH 3400, SPRING 2012
1. (Circle all that apply!) The dierential equation
x
dy
= y y2
dx
is
(a) separable
(b) linear
(c) exact
(d) Bernoulli
Answer: (a),(d)
2. The general solution of the equation
x = 2x 1
is
(a) x(t) = 1/2 cos 2t