Math 3200-001 Exam1
Closed book, closed notes, no calculators or other devices. One 3x5 handwritten card allowed, both sides.
1. Find the general solution of the dierential equation y = y 2 .
Solution. By separation of variable,
y2 y = 1
y 2 y dt =
1dt
y
3200 Spring 2014 Homework 1
1.2/2 What order is the dierential equation t4 y + y sin t = 6?
Solution: Order 1 because there is only 1st derivative.
2
1.2/9 (a) Show that y (t) = Cet is a solution of y 2ty = 0 for any value of the constant C .
(b) Determin
Math 3200-001 Spring 2014 Homework 2 solution
2.3/15 A tank initially contains 10 lb of salt in 200 gal of weater. A salt solution ows into
the tank at 3 gal/min and well-stirred out at the same rate. Inow salt concentration is ci (t) =
0.2 (1 + sin t) lb
Math 3200-001 Fall 2014 Practice exam 1 solutions 2/16/2014
Each problem is worth 0 to 4 points: 4=correct, 3=small error, 2=good
progress, 1=some progress 0=nothing relevant. If the result is correct, detailed justication is not important though all step
Math 3200-001 Spring 2014 Practice exam
Each problem is worth 0 to 4 points: 4=correct, 3=small error, 2=good
progress, 1=some progress 0=nothing relevant. All steps need to be present
so that your method is clear. Closed books and notes, but you are allo