# Textbook Homework

The assignments from Boyce and Diprima below
are due in class on the date indicated. You may feel
that you haven't worked enough problems in a section
to feel comfortable with the material -- if so,
do more problems.

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Homework #1 (Friday June 3)

1.1: 1,3,7,11,15

1.2: 1c,2b

1.3: 2,8,15

2.1: 18,22bc,25bc

2.2: 1,5,14,17,22

2.3: 1,9,12,13

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Homework #2 (Wed. June 8)

2.4: 2,8,10,14,28

2.5: 3,16a,25ab; also, another problem of your choice.

2.6: 2,4,12,28[see #23]

2.7: 2a

3.1: 2,6,10,15,18,22

3.2: 1,2,8,9,14,16

Homework #3 (Wed. June 15)

3.4: 2, 4, 6, 8, 18, 24, 40

3.5: 4, 16, 24, 28, 38

3.6: 2, 6, 10, 20a, 22a, 31

3.7: 2, 6, 10

3.8: 2, 7[show work!], 8, 16, 19

Homework #4 (Wed. June 22)

3.9: 1, 2, 10, 11, 12

8.1: 2a

8.5: 1,2

6.1: 2, 5a, 6

Optional: 6.1: 26, 27
(recommended for physics and math majors)

6.2: 2, 3, 7, 12, 17, 24, 30

6.3: 2, 4, 8, 13, 14, 17, 18, 20, 27, 29

Homework #5 (Wed. June 29)

[You have most answers in the book, so be sure to
show the work justifying your results.]

7.1: 1,4,5, 15, 16

[7.1 notes. In 1,4,5 give definitions for
the variables x_1, ... in terms of u and its derivatives.]

7.2: 1ac, 3a, 8ac, 10, 11, 12[show work as on p.370), 21c,
22, 25

7.3: 3, 6 ,7, 13,14, 15, 16

7.4: 5, 6

[7.4 notes. In problem 6(c):
justify the deduction. In problem 6(d):
show work as follows.
You are looking for the matrix A=A(t) such that x'=Ax for each of
the two given vectors x. So, let X=X(t) be the 2x2 matrix whose columns
are those given vectors. Now you are looking for A such that AX=X'.
Multiply both sides from the right by X^{-1} to find A.]

7.5: 1, 8, 16, 20, 24, 25, 27, 29, 31

[7.5 notes. In #31: also draw the phase
portrait for the following three cases:
alpha equals 1;
alpha is a little bigger than 1;
alpha is a little smaller than 1.]

Homework #6 (Wed. July 6)

[You have most answers in the book, so be sure to
show the work justifying your results.]

7.6: 3, 13, 14

7.7: 3, 12

7.8: 1, 15

7.9: 1, 3

9.1: 1, 2, 5 [In 1,2,5: do parts a and b, and
the first half of part c -- sketch several trajectories];
13

9.2: 15, 16, 21

9.3: 1, 3, 5, 7