(b) 
15. (n + 1)/2n for n > 1.
21. Using mathematical induction, one can show that:
(a)
(b)
(c) Fn-1 + Fn+1 = Ln.
Chapter 6, page 46
1. (a) 4,845. (b) 3,003. (c) -2,912.
3. a = -3, b = 2, c = 0.
7. 1, -1, 1, -1, 1, -1.
11.
15. (d/2)n2 + [a - (d/2)]n.
19.
and 
These
are not always equal, since, for example, they are unequal for a1
= a2 = b1 = b2 =
1.
23. (1/6)n3 - (1/2)n2 + (1/3)n.
25. n3 + 5n.
27. s = 3, t = 1.
29. r = 6, s = 7, t = 1.
31. (1/5)n5 + (1/2)n4 + (1/3)n3 - (1/30)n.
37. (n3 + 3n2 + 2n)/6.