Problem Set V

for Thursday, February 23

Due at Adrian Ioana's office hours, or earlier.

Section 2.6, page 59:

• Problem 6. Support your answer.
• Problem 8. It is assumed that each I_k is non-empty. What if we change "closed" to "open"?

Section 3.1, page 79:

• Problem 5.
• Problem 11.
• Also: Let f be the function on R for which f(x) = 0 whenever x is irrational, and f(p/q) = 1/q for each rational p/q (in lowest terms, with q in N). For what values of c, if any, is f continuous at c?