Page 285 - Calculus Demystified

272
y Solutions to Exercises

y

x x

(e) (f)

10. (a) Each person has one and only one father. This is a function.
(b) Some men have more than one dog, others have none. This is not a
function.
(c) Some real numbers have two square roots while others have none.
This is not a function.
(d) Each positive integer has one and only one cube. This is a function.
(e) Some cars have several drivers. In a one-car family, everyone drives
the same car. So this is not a function.
(f) Each toe is attached to one and only one foot. This is a function.
(g) Each rational number succeeds one and only one integer. This is a
function.
(h) Each integer has one and only one successor. This is a function.
(i) Each real number has a well defined square, and adding six is a well
defined operation. This is a function.

11.

(a) (b)