The top and bottom margins of a poster are 3 cm and the margins on the sides are 2 cm. If the print area on the poster is set to 96 cm2, find the dimensions of the poster with the smallest area.
wide:
height:
If the print area is
x cm wide
y cm tall, then xy = 96
That makes the whole poster area
a = (x+4)(y+6) = (x+4)(96/x + 6) = 6x+120 + 384/x
da/dx = 6 - 384/x^2
da/dx=0 at x=8 and y=12