The top and bottom margins of a poster are 2 cm and the side margins are each 8 cm. If the area of printed material on the poster is fixed at 388 square centimeters, find the dimensions of the poster with the smallest area.

Question

anonymous · Answer

I've done this problem about 10 times now and It still isn't right! What am I doing wrong!?!?

area = (x+4)(388/x +16)

darea/dx = (x+4)(-388/x²) +(388/x +16)

x = sqrt(97) = 9.84

width = 9.84
length = 9.84 + 16 = 25.84

anonymous · Answer

@Mertsj (You've helped me before I was hoping maybe you could help me again! Haha :P)

mertsj · Answer

|dw:1367368866783:dw|
$$(x+4)(\frac{388}{x}+16)=388+16x+\frac{1552}{x}+64=16x+1552x ^{-1}+452$$