Download 3,5,7,9,11,... is an arithmetic sequence with initial term 3 and

66
9. RATIONAL NUMBERS, REAL NUMBERS, AND ALGEBRA
3, 5, 7, 9, 11, . . .
is an arithmetic sequence with initial term 3 and common di↵erence 2, i.e.,
successive terms di↵er by 2. The form is
a, a + d, a + 2d, a + 3d, . . . .
2, 6, 18, 54, 162, . . .
is a geometric sequence with initial term 2 and common ratio 3, the number
each successive term is multiplied by. The form is
a, ar, ar2, ar3, . . . .
3) f : W ! W defined by f (n) = n3 assigns each whole number (the domain)
to its cube.
Problem (Page 408 # 8).
a) is a function for a given election, but may not be in general.
b) not a function since many large cities, such as Memphis, have seral zip codes.
c) is a function (if I understand my biology).
d) is not a function since a person may have more than one pet.