Question

An open top box with rectangular base is to be constructed. The box is to be at least 2 inches wide and twice as long as it is wide. It is to have a volume of 150 cubic inches. What should the dimensions of the box be if the surface area is to be as small as possible?

Answer 1

So, length(l)=2*breadth(b)

Answer 2

right?

Answer 3

yeah area would =2xy

Answer 4

Now, u know the formula for VOLUME OF A CUBOID?

Answer 5

i dont think so

Answer 6

Volume of a cuboid=l*b*h

Answer 7

got it?

Answer 8

sure

Answer 9

where do i go from there?

Answer 10

Also, Volume =150

Answer 11

given right?

Answer 12

yes that was given

Answer 13

im still not sure how to put this together to reach an answer

Answer 14

OK:
VOlume=150
l*b*h=150
l*2l*h=150
h=75/l^2

Answer 15

got it?

Answer 16

so height is 75?

Answer 17

Nope

Answer 18

Now, we have,
b=2l
h=75/l^2

Answer 19

got it?

Answer 20

@skallan01 ???

Answer 21

yeah i got it

Answer 22

Now,
S.A of that rectangular box = 2(l+b)*h + l*b

Answer 23

following?

Answer 24

ok i think i can take it from there,thank you

Answer 25

WELCOME