PreCalc
posted by Andy G on .
A page that is x inches wide and y inches high contains 30 square inches of print. The top and bottom margins are 2 inches deep, and the margins on each side are 2 inches wide.
a. draw a diagram that gives a visul representation of the problem.
b. show that the total area A on the page is A=2x(2x+7)/(x4)
c. determine the domain of the fuction based on the physical constraints of the problem.
d. use a graphing utility to graph the area function and approximate the page size for which the least amount of paper will be used.

if the page is x by y
then the printable area = x4 by y4
so (x4)(y4) = 30
xy 4x  4y + 16 = 30
xy  4y = 4x + 14
y(x4) = (4x+14)
y = (4x+14)/(x4)
Total area = xy
= x(4x+14)/(x4)
= 2x(2x+7)/(x4) > that would be b)
c) clearly x> 4
d) your job with the graphing utility stuff