Chapter 1.1, Problem 50E

Impact of Mad Cow Disease on Canadian Beef Exports The discovery of one case of bovine spongiform encephalopathy, or mad cow disease, in May $2003$ in Canada led to an immediate ban on all Canadian beef exports. At the beginning of September $2003$, the ban was lifted, and exports of Canadian beef rose at a steady rate $\$42.5$ million per month. Express the value of the monthly exports of Canadian beef as a function of time for the period starting the first day of September $2003$. What was the value of the monthly exports at the end of December $2003$, when presumably the exports regained their normal level? (Source.- International Trade Division Statistics, Canada)