Answer:
of square should be cut out of each corner to create a box with the largest volume.
Step-by-step explanation:
Given: Dimension of cardboard= 16 x 30“.
As per the dimension given, we know Lenght is 30 inches and width is 16 inches. Also the cardboard has 4 corners which should be cut out.
Lets assume the cut out size of each corner be "x".
∴ Size of cardboard after 4 corner will be cut out is:
Length (l)= ![30-2x](https://tex.z-dn.net/?f=30-2x)
Width (w)= ![16-2x](https://tex.z-dn.net/?f=16-2x)
Height (h)= ![x](https://tex.z-dn.net/?f=x)
Now, finding the volume of box after 4 corner been cut out.
Formula; Volume (v)= ![l\times w\times h](https://tex.z-dn.net/?f=l%5Ctimes%20w%5Ctimes%20h)
Volume(v)= ![(30-2x)\times (16-2x)\times x](https://tex.z-dn.net/?f=%2830-2x%29%5Ctimes%20%2816-2x%29%5Ctimes%20x)
Using distributive property of multiplication
⇒ Volume(v)= ![4x^{3} -92x^{2} +480x](https://tex.z-dn.net/?f=4x%5E%7B3%7D%20-92x%5E%7B2%7D%20%2B480x)
Next using differentiative method to find box largest volume, we will have ![\frac{dv}{dx}= 0](https://tex.z-dn.net/?f=%5Cfrac%7Bdv%7D%7Bdx%7D%3D%200)
![\frac{d (4x^{3} -92x^{2} +480x)}{dx} = \frac{dv}{dx}](https://tex.z-dn.net/?f=%5Cfrac%7Bd%20%284x%5E%7B3%7D%20-92x%5E%7B2%7D%20%2B480x%29%7D%7Bdx%7D%20%3D%20%5Cfrac%7Bdv%7D%7Bdx%7D)
Differentiating the value
⇒![\frac{dv}{dx} = 12x^{2} -184x+480](https://tex.z-dn.net/?f=%5Cfrac%7Bdv%7D%7Bdx%7D%20%3D%2012x%5E%7B2%7D%20-184x%2B480)
taking out 12 as common in the equation and subtituting the value.
⇒ ![0= 12(x^{2} -\frac{46x}{3} +40)](https://tex.z-dn.net/?f=0%3D%2012%28x%5E%7B2%7D%20-%5Cfrac%7B46x%7D%7B3%7D%20%2B40%29)
solving quadratic equation inside the parenthesis.
⇒
=0
Dividing 12 on both side
⇒
= 0
We can again take common as (x-12).
⇒
=0
∴![(x-\frac{10}{3} ) (x-12)= 0](https://tex.z-dn.net/?f=%28x-%5Cfrac%7B10%7D%7B3%7D%20%29%20%28x-12%29%3D%200)
We have two value for x, which is ![12 and \frac{10}{3}](https://tex.z-dn.net/?f=12%20and%20%5Cfrac%7B10%7D%7B3%7D)
12 is invalid as, w= ![(16-2x)= 16-2\times 12](https://tex.z-dn.net/?f=%2816-2x%29%3D%2016-2%5Ctimes%2012)
∴ 24 inches can not be cut out of 16 inches width.
Hence, the cut out size from cardboard is ![\frac{10}{3}\ inches](https://tex.z-dn.net/?f=%5Cfrac%7B10%7D%7B3%7D%5C%20inches%20)
Now, subtituting the value of x to find volume of the box.
Volume(v)= ![(30-2x)\times (16-2x)\times x](https://tex.z-dn.net/?f=%2830-2x%29%5Ctimes%20%2816-2x%29%5Ctimes%20x)
⇒ Volume(v)= ![(30-2\times \frac{10}{3} )\times (16-2\times \frac{10}{3})\times \frac{10}{3}](https://tex.z-dn.net/?f=%2830-2%5Ctimes%20%5Cfrac%7B10%7D%7B3%7D%20%29%5Ctimes%20%2816-2%5Ctimes%20%5Cfrac%7B10%7D%7B3%7D%29%5Ctimes%20%5Cfrac%7B10%7D%7B3%7D)
⇒ Volume(v)= ![(30-\frac{20}{3} ) (16-\frac{20}{3}) (\frac{10}{3} )](https://tex.z-dn.net/?f=%2830-%5Cfrac%7B20%7D%7B3%7D%20%29%20%2816-%5Cfrac%7B20%7D%7B3%7D%29%20%28%5Cfrac%7B10%7D%7B3%7D%20%29)
∴ Volume(v)= 725.93 inches³