Let A:= (0, oo) and let k: A-+ R be defined as follows. For x e A, x irrational, we define k(x) = 0; for x e A rational and of the form x = m/n with natural numbers m, n having no common factors except I, we define k(x) := n. Prove that k is unbounded on every open interval in A. Conclude that k is not continuous at any point of A. (See Example 5.1.6(h).)

ANS 2: Week 4 Notes (4/18) ● Mammary Gland Anatomy ○ Exocrine gland - secretes to outside of body ■ Developmentally like salivary + sudoriferous (sweat) glands ○ Defines the class mammalia ■ Range from skin surface milk patch (monotremes) ■ To variable number of defined glands ○...