<span> Let x = the width
Let 2x = the length
Let h = the height
</span>then vol = x*2x*h. So we have 2x^2*h = 24
h=24/(2*x^2)=12/x^2
Surface area: two ends + 1 bottom + 2 sides (no top)
S.A. = 2(x*h) + 1(2x*x) + 2(2x*h)
S.A. = 2xh + 2x^2 + 4xh<span> S.A. = 2x^2 + 6xh
</span>Replace h with 12/x^2
S.A = 2x^2 + 6x(12/x^2)
S.A = 2x^2 + 6(12/x)
S.A = 2x^2 + (72/x)
Graph this equation to find the value of x for minimum material
Min surface area when x = 3.0 is the width<span> then
</span>2(3) = 6 is the length
Find the height:
h=12/(3.0)^2
h=1.33
Box dimensions for min surface area: 3.0 by 6 by 1.33; much better numbers
Check the vol of these dimensions: 3.0*6*1.33 ~ 24
graphic attachment
Use Pythagoras to get the height, the use it to find x:
26^2-11^2 =555
555^1/2(square root of 555)
=23.55843798 ~you need this number left as it is for a more accurate answer.
Then you do
42^2-23.55...^2(which we know is 555)
Then whatever that equals you square root that
Then you round up the answer to that to get the final answer.
I left the last part so you can do it and do some active learning, if you have more questions on this please feel free to ask, hope this helps
Lean is 5 and the quasretiv