Question

You are designing a rectangular poster to contain 50 in^2 of printing with a 4 in. margin at the top and bottom and a 2 inch margin at each side. What overall dimensions will minimize the amount of paper used?

Answer 1

You have say length and width of the printable area as x and y respectively..

then xy = 50 ..

Now you have total length and width (including margins) as (x + 2*4) and (y + 2*2) respectively. You need to minimize (x + 2*4)(50/x + 2*2). Differentiate this wrt x to get x = 10 and y = 5 ..

Answer 2

My textbook says 18 and 9.

Answer 3

dude I gave you the dimensions of the printing area ... now add 4*2 and 2*2 to the respective dimensions to get the net dimension = 18 and 9

Answer 4

Ah, didn't read your reply completely. Thanks for the response.