M251ex1(fa10) - MATH 251 Name Examination I Student Number...

MATH 251
Examination I
September 27, 2010
FORM A
Name:
Student Number:
Section:
This exam has 14 questions for a total of 100 points. Show all you your work! In order to obtain
full credit for partial credit problems, all work must be shown. Credit will not be given
for an answer not supported by work. For other problems, points might be deducted,
at the sole discretion of the instructor, for an answer not supported by a reasonable
amount of work. The point value for each question is in parentheses to the right of the question
number.
You may not use a calculator on this exam. Please turn off and put away your
cell phone.
1 :
2
thru
10:
11:
12:
13:
14:
Total:
Do not write in this box.

EXAMINATION I September 27, 2010
1. (8 points) Consider the differential equation
y
0
=
sin t
y + e y
.
Answer the following questions.
(a) (2 points) Is the equation linear ?
(b) (2 points) Is the equation separable ?
(c) (2 points) Is the equation exact ?
(d) (2 points) Is the equation autonomous ?
2. (5 points) Which of the equations below is a second order linear differential equation?
(a)