# Errata

## for: Difference Equations: An Introduction With Applications, Second Edition, Academic Press, New York (2001) (with Walter Kelley)

- Page viii, line 1-,2-: Replace "Hankserson" by "Hankerson".
- Page 33, line 8-: Replace ".." by ".".
- Page 38, line 10: Replace "2.15" by "2.16".
- Page 40, Exercise 2.34: In part b, the summation on
the left-hand side of the equation should contain a (-1)^n.
- Page 60, line 9-: Replace "y" by "u".
- Page 110, line 2-: Need "?" at the end of the sentence.
- Page 118, line 19: Omit the second "y" in this equation.
- Page 120, line 15: Replace "$\frac{tial f}{tial y}$" by "$\frac{\partial f}{\partial y}$"
- Page 153, line 12: Replace "1" by "0".
- Page 154, line 11: Replace "theorem" by "lemma".
- Page 154, line 1-: Put a "0" in the upper right hand corner of the matrix.
- Page 156, line 22: Replace second "A(p-1)" by "A(p-2)".
- Page 156, line 24: This is a bad mistake (I really do know that matrices don't commute in general).
See correction on my web site to fix this proof up.
- Page 175, In top figure replace "a>3" by "a=3"
- Page 187, Exercise 4.3: Add the asumption that "b is the fraction of juveniles each year that remain juveniles."
- Page 232, The two matrices on this page should be determinants.
- Page 236, The four matrices on this page should be determinants.
- Page 254, line 7- lower limit of summation should be s=a+1.
- Page 284, line 5- Replace "q(t)>0" by "q(t)<0"
- Page 285, line 6 Replace "r(z)" by "r(t)"
- Page 285, line 5- Replace "q(t)>0" by "q(t)<0"
- Page 289, line 5 "y_k(t)=sin(\frac{k\pi t}{4})"
- Page 289, line 13 Replace "sin(\frac{k\pi }{4})" by "sin(\frac{k\pi t}{4})"
- Page 294, line 11-: Replace "6.6" by "6.7".
- Page 377, line 8-: Replace "A saddle with no reflection (case 8)." by "A saddle with double reflection (not considered in text).".
- Page 380, Answer to Exercise 7.11 should be
w(t)=(-1-\frac{\sqrt{2}}{2})\sin(\frac{\pi t}{4}+\sin{\frac{\pi t}{2}}+(1-\frac{\sqrt{2}}{2}}\sin(\frac{3\pi t}{4})