Chapter 4.2, Problem 81E

A page that is $x$ inches wide and $y$ inches high contains 30 square inches of print. The top and bottom margins are each 1 inch deep and the margins on each side are 2 inches wide (see figure).

(a) Show that the total area A of the page is

$A=\frac{2x(x+11)}{x-4}$

(b) Determine the domain of the function based on the physical constraints of the problem.

(c) Use a graphing utility to graph the area function and approximate the dimensions of the page that use the least amount of paper. Verify your answer numerically using the table feature of the graphing utility.