If the dimensions are x wide and y high, then
y = 160/x
The printed area is
a = (x-2)(y-1-7) = (x-2)(160/x - 8) = 176-8x-320/x
da/dx = -8+320/x^2
da/dx=0 when x=2√10
Now figure y and you're done.
A poster is to have an area of 160 in2 with 1 inch margins at the bottom and sides and a 7 inch margin at the top. What dimensions will give the largest printed area? (Give your answers correct to one decimal place.)
1 answer