Chapter 1.1, Problem 72E

The Postage function.

The cost of sending a large envelope via U.S. first-class mail in 2014 was $0.98 for the first ounce and $0.21 for each additional ounce (or fraction thereof). (Source; www.usps.com.) If x represents the weight of a large envelope, in ounces, then $p\left(x\right)$ is the cost of mailing it, where

$\begin{array}{l}p\left(x\right)=\$0.98,\text{if}0<x\le 1,\\ p\left(x\right)=\$1.19,\text{if}1<x\le 2,\\ p\left(x\right)=\$1.40,\text{if}2<x\le 3,\end{array}$

And so on, up through 13 ounce. The graph of p is show below.

Using the graph of the postage function, find each of the following limit, if it exists.

$\underset{x\to 1^{-}}{\lim }p\left(x\right),\underset{x\to 1^{+}}{\lim }p\left(x\right),\underset{x\to 1}{\lim }p\left(x\right)$