Chapter 2.2, Problem 35E

 Postage rates Assume postage for sending a first-class letter in the United States is $0.47 for the first ounce (up to and including 1 oz) plus $0.21 for each additional ounce (up to and including each additional ounce).

  a    Graph the function p = f(w) that gives the postage p for sending a letter that weighs w ounces, for 0 < w ≤ 3.5.

  b.    Evaluate $\underset{w\to 2.3}{\lim }f\left(w\right)$

  c.    Does $\underset{w\to 3}{\lim }f\left(w\right)$ exist? Explain