Answer:
The value of x that maximizes the volume enclosed by this box is 0.46 inches
The maximum volume is 3.02 cubic inches
Step-by-step explanation:
see the attached figure to better understand the problem
we know that
The volume of the open-topped box is equal to
![V=LWH](https://tex.z-dn.net/?f=V%3DLWH)
where
![L=(7-2x)\ in\\W=(2-2x)\ in\\H=x\ in](https://tex.z-dn.net/?f=L%3D%287-2x%29%5C%20in%5C%5CW%3D%282-2x%29%5C%20in%5C%5CH%3Dx%5C%20in)
substitute
![V=(7-2x)(2-2x)x](https://tex.z-dn.net/?f=V%3D%287-2x%29%282-2x%29x)
Convert to expanded form
![V=(7-2x)(2-2x)x\\V=(14-14x-4x+4x^{2})x\\V=14x-14x^2-4x^2+4x^{3}\\V=4x^{3}-18x^{2} +14x](https://tex.z-dn.net/?f=V%3D%287-2x%29%282-2x%29x%5C%5CV%3D%2814-14x-4x%2B4x%5E%7B2%7D%29x%5C%5CV%3D14x-14x%5E2-4x%5E2%2B4x%5E%7B3%7D%5C%5CV%3D4x%5E%7B3%7D-18x%5E%7B2%7D%20%2B14x)
using a graphing tool
Graph the cubic equation
Remember that
The domain for x is the interval -----> (0,1)
Because
If x>1
then
the width is negative (W=2-2x)
so
The maximum is the point (0.46,3.02)
see the attached figure
therefore
The value of x that maximizes the volume enclosed by this box is 0.46 inches
The maximum volume is 3.02 cubic inches