MAT 3306, Differential Equations, Spring 2013

9. An Exellent Textbook for Differential Equations in pdf format

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Homework Assignments

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Note: On all emails for this course, start the subject line out with
MAT3306, followed by whatever else is appropriate. Emails without this
subject line formatting may not be accepted!

HW1:  1.1, pg 5, #'s 1-9 odd; R&S 1.2
Here is a copy of the problems for HW1
Due: Start of class on Monday, 1/14
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HW2:  1.2, pgs 11-13, #'s 1c,1d,2a,3a,5b,6a; R&S 1.3
Here is a copy of the problems for HW2
Due: Start of class on Wednesday, 1/16
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HW3:  1.3, pgs 21-23, #'s 1,3,5,7; R&S 2.1
Here is a copy of the problems for HW3
Due: Start of class on Monday, 1/21
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HW4:  2.1, pgs 36-37, #'s 1,5,7,9,11,13,15;
Here is a copy of the problems for HW4
Due: Start of class on Wednesday, 1/23
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HW5:  2.1, pgs 36-37, #'s 21 and 23; R&S 2.2
Due: Start of class on Monday, 1/28
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HW6:  2.2, pgs 46-47, #'s 1-13 odd;
Due: Start of class on Wednesday, 1/30
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HW7:  2.2, pgs 46-47, #'s 15-19 odd, finish solving the homogeneous problems from 1-13;
R&S 2.3
Due: Start of class on Monday, 2/4
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HW8:  Finish any unfinished hw, R&S 2.3;
Due: Start of class on Wednesday, 2/6
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HW9:  2.3, pgs 56-57, 1-13 odd,19,21,23
Here is a copy of the examples for today.
Here is a copy of the handout for today.
Due: Start of class on Monday, 2/11
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HW10:  2.3, pgs 56-57 # 25, pg 60 #'s 19,21; R&S 2.4
Here is a copy of sample problems over bernoulli ODE's from a previous semester
Due: Start of class on Wednesday, 2/13
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HW11: 2.4, pg 67, #'s 1,3,7,13; R&S 3.1
Do each of these problems and turn a copy of them in.
This will count as one problem on your mid-term.
Do a very nice job - neat handwriting and don't skip any steps.
Due: Start of class on Monday, 2/18
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HW12: R&S 3.2
Due: Start of class on Wednesday, 2/20
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HW13: 3.2 #'s 1-7, 13,15; R&S 3.3
Due: Start of class on Monday, 3/4
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HW14: 3.3 #'s 1-15 odd;
I will select a couple of these problems to turn in as a take-home question
for the mid-term.
Note: I found a mistake in the textbook answer for problem 1. The correct answers are
a) 34.9%  and b) 1315.8 years. I'll let you know if I find any others!
Notes from Monday's lecture on section 3-3
Due: Start of class on Wednesday, 3/6
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Midterm - Take-Home Problem 1:

A 900 gallon tank contains 300 gallons of brine in which 10 lb of salt is
dissolved. Starting at time, t = 0, brine containing 2 lb of salt per gallon
flows into the tank at the rate of 6 gal/min. The mixture is kept uniform by
stirring and the well-stirred mixture leaves the tank at the rate of 2 gal/min.
Solve this differential equation and answer the following questions:

a) How much salt is in the tank after 10 minutes?

b) When (if ever) will there be 100 lbs of salt in the tank?

c) What is the greatest amount of salt that will ever be in the tank?

Midterm - Take-Home Problem 2:

A pan of hot water is removed from the stove and placed on a counter to cool.
At this instant, the temp of the water was 213 degrees F. Eleven minutes later
the temp is 190 degrees F. If the surrounding temp is 80 degrees F, answer the
following questions:

a) What is the temp after 45 minutes?

b) When will the temp be 98.6 degrees F. ?

c) If, after sitting one hour on the counter, the pan of water is moved
outside where the temp is 40 degrees F, what will the temp be an additional
30 minutes after that?

These are due at the start of class on Monday. Feel free to compare your answers
with your classmates, but do NOT share your work with them. If, after comparing
answers and each reworking the problem to try to correct mistakes, then you still
have different answers, you may collaborate to correct any mistakes. In any case,
each student must have a complete, neat, writeup of all work necessary to find

HW15: R&S 4.1
Due: Start of class on Monday, 3/24
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HW16:  4.1 pgs 132-133 1,3,5,7
Due: Start of class on Wednesday, 4/10
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HW17:  4.2 pgs 143-144 Problems 1-9
Due: Start of class on Monday, 4/15
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HW18:  pgs 160-162
Andrew: 59, 9, 39
Caleb: 53, 7, 37
Jesse: 55, 5, 41
Ross Examples 36-38 on pages 155-159.
Have these written up nicely as if you were going to turn them in.
I will ask you to put one of these up on the board Wednesday.
Due: Start of class on Wednesday, 4/17
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HW19:  pgs 160-162
Andrew: 57, 25, 47
Caleb: 59, 17, 43
Jesse: 61, 11, 45

Have these written up nicely and ready to turn in. This is a
take home problem for the final. They should be at least as clear
and easy to follow as the ones I put up on the board and website
last class meeting.
Due: Start of class on Monday, 4/22
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Here are some sample problems from another semester and textbook. There
may be some helpful material here (of course there may also be some that is

Higher Order Homogeneous ODEs - Paul's pgs 116-120
Higher Order Non-Homogeneous ODEs - Paul's pgs 139-143
Higher Order Non-Homogeneous ODEs - Find y sub p only problems - Paul's pgs 145-150

The final exam for our course (MAT3306.01) is Wednesday, May 2nd from 7:45 - 9:45 am.

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